World 4 (Dr. Mario World)

World 4 is a haunted forest world in Dr. Mario World. It is available since the initial version of this game.

When an area is cleared, Boos and Peepas appear. The viruses featured in the regular stages are red, green and light-blue.

Stage names in bold red text are labelled as hard stages in the game.

Area 1

Image	Stage	Best Doctors	Overview
	Stage 121	Dr. Yoshi Dr. Toad	This stage introduces dust viruses, which are viruses that are hidden in dust until a capsule lands next to it or an adjacent object is destroyed. If a valid match is made even though viruses in dust are not revealed, it will still be eliminated. The objective of this stage is to eliminate all viruses. This stage is shaped like a ghost, with exploders shaping its eyes. Some Brick Blocks are present in this stage.
	Stage 122	Dr. Lakitu Dr. Luigi	The objective of this stage is to eliminate all viruses. In this stage, there is a path of viruses interspersed with dust viruses. A red lock block is located between two Empty Blocks, which will unlock red cages containing viruses and a green lock block. The green cages contain viruses and Brick Blocks.
	Stage 123	Dr. Ludwig Dr. Waluigi	The objective of this stage is to eliminate all viruses. In this stage, viruses are lined up along the sides, top and a row near the bottom, with most of them being half-frozen. In the middle, dust viruses are found above Empty Blocks.
	Stage 124	Dr. Fire Rosalina Dr. Toad	The objective of this stage is to eliminate all viruses. In this stage, cages are lined up diagonally, one line containing viruses and another containing Floatie Viruses. The corresponding lock blocks are found on the outside of the diagonal line with Brick Blocks.
	Stage 125	Dr. Luma Dr. Fire Mario	The objective of this stage is to collect all virus coins. In this stage, there are two groups with two columns each has viruses each with four virus coins each, and in each group, the ones in the middle rows are half-frozen. In the middle column, there are fully-frozen viruses with exploders, and each virus cover a virus coin. Two columns with Brick Blocks and Empty Blocks are located between the middle column. The capsule amount is increased from 32 to 37 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 126	Dr. Toadette Dr. Yoshi	The objective of this stage is to eliminate all viruses. In this stage, a shell is in the middle of the stage where it is in the same row as two lock blocks and two Floatie Viruses. The cages form both a "v" and an upside-down "v". The Brick Blocks contain hidden viruses.
	Stage 127	Dr. Waluigi Dr. Toad	The objective of this stage is to eliminate all viruses. This stage is shaped like a spade that is mostly formed by dust viruses and a half-frozen lock block in the middle that corresponds to four caged viruses in the corners.
	Stage 128	Dr. Baby Rosalina Dr. Fire Mario	The objective of this stage is to eliminate all viruses. In this stage, there are two symmetrical groups of viruses that are in cages with the middle ones being free. There are viruses inside bubbles surrounded by Brick Blocks on the leftmost and rightmost columns, and a shell in the middle column in the top row. The Brick Blocks in the second and eighth columns contain lock blocks in the second row and hidden viruses in the others. The capsule amount is increased from 40 to 45 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 129	Dr. Mario Dr. Waluigi	The objective of this stage is to eliminate all viruses. In this stage, dust viruses are in the leftmost and rightmost columns, along with one in the middle column in the topmost row. Hidden viruses are found in Brick Blocks, and some viruses are half-frozen and fully-frozen.
	Stage 130	Dr. Yoshi Dr. Wendy	The objective of this stage is to collect all coins from Coin Blocks. This stage is shaped like a flower. Viruses in cages are found next to Brick Blocks (all containing coins), with the corresponding lock block near the bottom. An exploder is in the middle of the Brick Blocks.
	Stage 131	Dr. Fire Peach Dr. Fire Mario	The objective of this stage is to eliminate all viruses. This stage is shaped like a ghost flipped 90 degrees to the left. Three Floatie Viruses are found in the sixth row. Three dust viruses are found in the fifth to seventh rows each found in one row. Half-frozen viruses can be found in the first three columns. Hidden viruses are found in the Brick Blocks in the seventh column except for the one in the middle.
	Stage 132	Dr. Toadette Dr. Baby Rosalina	The objective of this stage is to eliminate all viruses. This stage is shaped like a clock pointing to 8 o' clock, with the hands formed by dust viruses all containing Floatie Viruses.
	Stage 133	Dr. Fire Peach Dr. Peach	The objective of this stage is to eliminate all viruses. In this stage, viruses (normal, caged and half-frozen) and a few dust viruses are found in the odd-numbered columns, with Floatie Viruses inside bubbles found in the even-numbered columns. The Brick Block contains a hidden lock block, and the lock block in the rightmost column is fully-frozen. The lock block in the middle column is locked behind a cage.
	Stage 134	Dr. Fire Rosalina Dr. Fire Peach	The objective of this stage is to eliminate all viruses. In this stage, there are viruses in bubbles and hidden viruses in all the Brick Blocks. Exploders are found in the middle column and the topmost row, and a shell is found in the topmost row at the middle column.
	Stage 135	Dr. Wario Dr. Wendy	The objective of this stage is to collect all coins from Coin Blocks. In this stage, the Floatie Viruses are surrounded by viruses in a "+" pattern, except for the bottom-most row ones where the bottom is open. All Brick Blocks in this stage contain coins.
	Stage 136	Dr. Waluigi Dr. Yoshi	The objective of this stage is to eliminate all viruses. In this stage, four Capsule Plus capsules are found along the fifth and eighth rows, along Floatie Viruses. The second row contains viruses and a Floatie Virus. All Brick Blocks contain hidden viruses. Purple coins are unlocked in the following sequence: Three coins from the left side in the tenth row and second coin in the fourth row Third coin in the first row, fourth coin in the second row and first and third coins in the seventh row First coin in the first row, second coin in the seventh row and the rest of the coins in both the fourth and tenth rows Remaining coins in the first and seventh rows.
	Stage 137	Dr. Luigi Dr. Toad	The objective of this stage is to eliminate all viruses and collect all keys. In this stage, rows of colorful crates are found below rows of cages and doors, with three colors of Lock Blocks found in the middle column. The capsule amount is increased from 39 to 46 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 138	Dr. Bowser Dr. Waluigi	The objective of this stage is to eliminate all viruses. In this stage, three rows of yellow and light-blue viruses are placed in a checkered pattern with crates in between. Red viruses are found above those three rows, with an outside layer of partially damaged barrels containing them, a middle layer of half-frozen viruses and fully-frozen viruses on the inside. An extra row of crates are found in the top-most row.
	Stage 139	Dr. Waluigi Dr. Baby Mario	The objective of this stage is to eliminate all viruses and collect all pink coins from Brick Blocks. In this stage, Floatie Viruses of each color in groups of three are found in clouds lined up in three columns. Brick Blocks in the third, fifth and seventh columns contain pink coins, while the others do not contain anything. Additionally, colorful crates are found on the columns that the Floatie Viruses do not occupy in the beginning. The filled flask in this stage will shoot out either colorful crates or exploders.
	Stage 140	Dr. Koopa Troopa Dr. Bowser	The last stage of the first area, the objective of this stage is to eliminate all viruses, collect all pink coins in Brick Blocks and collect all purple coins. In this stage, there are three rows of barriers alternating between three rows of viruses, with one barrier in each row being the odd one out in terms of being active. A row of purple coins found partially damaged barrels are located at the top of the stage before it scrolls, with an additional five coins above that row. On the rows above the initial seven rows of this stage, additional viruses are found in the leftmost and rightmost columns, three of them being Floatie Viruses of different colors. More viruses are found between Brick Blocks found on the second and eighth rows, along with purple coins found in barrels in between those rows. At the top of the stage, four Brick Blocks are found with a caged purple coin between them. The purple coins in the undamaged barrels require other purple coins to be collected, while the single one in the top requires the other purple coins to be collected. This stage will scroll for one line each time enough objects are cleared, and will stop after 8 lines are introduced. When cleared, the rest of the first area in the world map gets cleared of viruses. Players also obtain 500 coins upon completing this stage. Prior to version 1.3.5, the stage layout was different. The following changes were made: Two viruses are added in the second row from top after the stage scrolled up all the way, in the rightmost two columns.

Area 2

Image	Stage	Best Doctors	Overview
	Stage 141	Dr. Bowser Dr. Yoshi	The objective of this stage is to eliminate all viruses, including any that appears from flasks. In this stage, there are two medium-sized flasks and two rows of Empty Blocks separating two groups of barrels each arranged in a zig-zag line, with viruses found within the right-angled curves. Four more viruses are found in barrels in the top half, while the rest of the barrels contain exploders. Filled flasks in this stage will shoot out viruses.
	Stage 142	Dr. Fire Mario Dr. Luigi	The objective of this stage is to collect all keys. In this stage, bubble viruses and colorful crates are arranged in diagonal lines, with every colorful crate found in partially damaged barrels except for the ones in the bottom-most row.
	Stage 143	Dr. Yoshi Dr. Fire Mario	The objective of this stage is to eliminate all viruses and destroy all barries. In this stage, barriers found in barrels form two overlapping circles. Barriers found in barrels will not change state until the barrel is broken. Prior to version 1.3.5, the stage layout was different. The following changes were made: Capsule amount is increased from 40 to 43. Floatie Viruses are half-frozen instead of fully-frozen.
	Stage 144	Dr. Baby Luigi Dr. Waluigi	The objective of this stage is to eliminate all viruses. In this stage, two groups of six viruses are surrounded by crates and a few colorful crates, and one group of virus is behind colorful crates and Empty Blocks. Additionally, seven Capsule Plus capsules are found throughout the stage, one of which is next to one group of viruses surrounded by crates.
	Stage 145	Dr. Baby Peach Dr. Diddy Kong	The objective of this stage is to eliminate all viruses and collect all pink coins from Brick Blocks. a row of eight red Floatie Viruses are found between a row of Brick Blocks and red colorful crates, and four additional Floatie Viruses are found above the group of Brick Blocks. Colorful crates are lined up on the sides above the group of Brick Blocks, along with two in the middle that are surrrounded by viruses. Every Brick Block contains coins.
	Stage 146	Dr. Lakitu Dr. Daisy	The objective of this stage is to eliminate all viruses and collect all keys. In this stage, viruses, half-frozen barriers and Brick Blocks intersect with one another. The Brick Blocks in the topmost row contain doors, while the rightmost Brick Block in the bottom-most row contains a key. The Brick Blocks surrounded by viruses contain hidden viruses except for two, which contain keys. The capsule amount is increased from 38 to 40 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 147	Dr. Kamek Dr. Fire Peach	The objective of this stage is to collect all Virus Coins. This stage is split into nine sections of three rows and three columns separated by colorful crates, and each section contains a Virus Coin. Several of the colorful crates are locked behind cages with its corresponding Lock Block in the middle section. Filled flasks in this stage will shoot out colorful crates.
	Stage 148	Dr. Koopa Troopa Dr. Fire Peach	The objective of this stage is to eliminiate all viruses and collect all purple coins. In this stage, two large groups of purple coins are found, separated by a line of half-frozen viruses. Next to each group are three shells and three Floatie Viruses. The Brick Block has a hidden purple coin. The order in which the coins are unlocked are the following: Two groups of six coins at the bottom half of the group and one coin in the Brick Block Two groups of six coins at the top half of the group Six coins that divided the two groups of six coins in both halves The remaining coins that surrounded the other coins (except for the one in the Brick Block)
	Stage 149	Dr. Bowser Dr. Baby Peach	The objective of this stage is to eliminate all viruses and collect all pink coins from Brick Blocks. In this stage, a group of viruses covered in dust are found in the middle, and a Lock Block locking colorful crates shaped in an upside-down "U" is found above a group of viruses. All Brick Blocks except for those in the same row as the Lock Block contain coins. The capsule amount is increased from 45 to 50 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 150	Dr. Baby Mario Dr. Mario	The objective of this stage is to eliminate all viruses. In this stage, a large group of viruses in a shape of a filled "8" is found next to crates. Filled flasks in this stage will shoot out crates of variable durabilities. Prior to version 1.3.5, the stage layout was different. The following changes were made: Capsule amount is increased from 30 to 33. The Empty Block in the fifth row is changed to a Brick Block.
	Stage 151	Dr. Luma Dr. Kamek	The objective of this stage is to collect all purple coins and collect all keys. In this stage, purple coins surround two groups of 3x5 viruses, one group being half-frozen and another group encased in bubbles. Purple coins can be found in broken and unbroken barrels, with some of them in the way between the keys and doors.
	Stage 152	Dr. Baby Mario Dr. Fire Mario	The objective of this stage is to eliminate all viruses. In this stage, colorful crates separated groups of viruses, along with a few individual viruses near Empty Blocks. The red Lock Block is surrounded by Empty Blocks, along with Exploders near the Lock Block. The dust hides viruses.
	Stage 153	Dr. Luma Dr. Fire Peach	The objective of this stage is to eliminate all viruses and collect all purple coins. In this stage, bubble viruses are found above purple coins found below crates, while caged purple coins are found above crates. A line of viruses are found directly below ice fans at the top of the stage. Purple coins are unlocked in the following sequence: The nine coins found along the bottom of the crates Coins found in the fourth and sixth columns The rest of the coins along the fourth row
	Stage 154	Dr. Luigi Dr. Peach	The objective of this stage is to eliminiate all viruses and destroy all barriers. In this stage, viruses are lined up vertically, save for a few lined up horizontally along the barriers. All Brick Blocks contain hidden viruses. A Capsule Plus is found in a partially damaged barrel at the top-middle part of the stage.
	Stage 155	Dr. Daisy Dr. Mario	The objective of this stage is to eliminate all viruses. In this stage, colorful crates form two horizontal lines and two vertical lines criss-crossed with each other, with viruses occupying the spaces in between, along with colorful crates shaped like a cross at the top-right corner separated by ice fans and a lone virus. The capsule amount is increased from 28 to 33 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 156	Dr. Baby Rosalina Dr. Baby Peach	The objective of this stage is to eliminate all viruses. In this stage, four lines containing Empty Blocks and crates are found separated by a column of bubbles in the middle, holding viruses, Floatie Viruses and a flask. Additional viruses are found along the lines of crates and Empty Blocks. The filled flask in this stage will shoot out bubble viruses.
	Stage 157	Dr. Donkey Kong Dr. Baby Rosalina	The objective of this stage is to eliminate all viruses, collect all pink coins from Brick Blocks and collect all purple coins. In this stage, the layout is symmetrical, save for the colors of the viruses and shells. Lock Blocks are found in the middle column, with crates behind the blue cages, Brick Blocks behind the yellow cages and viruses behind the red cages. All Brick Blocks contain coins. The order in which the purple coins are unlocked are as follows: Single coin on the leftmost column Single coin on the rightmost column Coins from both the second and eighth columns Rest of the coins found in the sixth row
	Stage 158	Dr. Daisy Dr. Fire Mario	The objective of this stage is to collect all keys. In this stage, the viruses form a shape of a bunny's head. Among the viruses, four Floatie Viruses of each of the three colors are found. Doors are found in the topmost row, while keys are initially located below the yellow viruses.
	Stage 159	Dr. Luigi Dr. Toad	The objective of this stage is to eliminate all viruses and collect all purple coins. In this stage, half-frozen viruses, exploders, shells and Brick Blocks are found, along with a few fully-frozen Brick Blocks and purple coins. The order in which the purple coins are unlocked are as follows: The two unfrozen coins and three fully-frozen coins The two middle coins in the fourth row The coins found in the middle three columns The rest of the coins found in the leftmost two columns and rightmost two columns Prior to version 1.3.5, the stage layout was different. The following changes were made: Capsule amount is increased from 40 to 46. The viruses in the eighth row are no longer hidden in Brick Blocks.
	Stage 160	Dr. Toad Dr. Bowser Jr.	The final stage is a scrolling stage that requires all viruses to be eliminated. In this stage, various Floatie Viruses are found in the beginning, along with Brick Blocks and viruses in barrels throughout the stages. Bubble viruses appear eventually, and later ice fans start to appear. Exploders later appear, and a couple of half-frozen viruses one line after that. A line of regular viruses are found near the top, with the top containing a line of Empty Blocks. This stage will scroll for one line each time enough objects are cleared, and will stop after 10 lines are introduced. Once it is cleared, the remaining area of the stage map gets cleared of viruses, and players can access World 5. Upon completion, players earn a free Staff Ticket that lets them unlock either a new doctor, a new assistant, or leveling up an existing doctor or assistant. Prior to version 1.2.0, the stage layout was different. The following changes were made: Capsule amount is increased from 48 to 55. In the beginning before the stage scrolls, the fifth row has a shell in the rightmost column instead of a Brick Block.

Challenge stages

Image	Stage	Best Doctors	Overview
	Stage 4A	Dr. Diddy Kong Dr. Baby Daisy	Within a 52 second time limit, players need to eliminate all viruses and collect all purple coins. In this stage, there are four rows of purple coins (both caged and uncaged) with Brick Blocks between them, along with rows of viruses between those rows where they are between the Brick Blocks. Purple coins are unlocked in the following sequence: The coins in the eighth row. The coins in the sixth row. The coins in the fourth row. The coins in the second row. Starting from version 1.2.0, completing this stage awards the player 500 coins.
	Stage 4B	Dr. Kamek Dr. Fire Mario	Within a 105 second time limit, players need to eliminate all viruses. In this stage, two rows of viruses are locked behind cages, with the lock blocks found among dust containing Floatie Viruses. Starting from version 1.2.0, completing this stage awards the player 500 coins.
	Stage 4C	Dr. Wario Dr. Wendy	Within a 75 second time limit, players need to eliminate all viruses. This stage is shaped like the letter "Z" where one group consists of regular viruses, one group consists of viruses inside bubbles and Brick Blocks. Among the Brick Blocks, one diagonal line of them are fully-frozen, another consists of two hidden viruses as well as six Floatie Viruses and another line do not contain anything. Completing this stage awards the player 1000 coins and a Staff Ticket (3 Hearts prior to version 1.2.0).

Special Stage

Image	Stage	Best Doctors	Overview
	Special Stage	Dr. Yoshi Dr. Wario	The objective of this stage is to eliminate all viruses. In the beginning, there are five columns of cages with Empty Blocks in between containing Floatie Viruses in the middle column, a lock block in the rightmost column and viruses in the others. The bottom-most row of Brick Blocks contain hidden viruses, while the Brick Blocks in the row above the cages. Additional Floatie Viruses appear when the stage scrolls up once, and in the three rows after that, more viruses and Brick Blocks each containing hidden viruses appear. This stage will scroll for one line each time enough objects are cleared, and will stop after 5 lines are introduced. Completing this stage awards the player 1000 coins and Dr. Luigi.

Stage layouts in previous versions

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  Stage 140 prior to version 1.3.5. Note the amount of viruses required to be eliminated.

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  Stage 143 prior to version 1.3.5

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  Stage 150 prior to version 1.3.5

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  Stage 159 prior to version 1.3.5

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  Stage 160 prior to version 1.2.0

Category:Haunted_Places Category:Dr. Mario World Worlds