File:Galaxy.jpg
Mario approaching a Galaxy currently orbited by a Speedy comet.

Prankster Comets are comets that appear in Super Mario Galaxy. They will appear from time to time in the orbits of the fifteen main galaxies, starting at the point when Mario or Luigi collect their thirteenth Power Star.

If the player travels to a galaxy when a Prankster Comet is in orbit, a special event will be triggered, which will usually change the gameplay of the level. Prankster Comets will only appear in galaxies after a specific Power Star in any given galaxy is collected. Also, when a Prankster Comet is in orbit, the player is forced to choose its level. No option is given to choose "normal" levels. However, there is a purple Luma near the Terrace who will shuffle the comets between available galaxies if fed twenty Star Bits.

By completing the event, the player will receive a Power Star. While a Prankster Comet is in orbit of a galaxy, players will need to completely restart the level each time they lose a life, instead of coming back at the last check point. Once a Prankster Comet's star has been collected, its star will become a selectable mission, only causing the comet to return to the corresponding galaxy at the player's request. All of the Prankster Comets also have their own music that plays during their missions.

There are five different types of Prankster Comets, each one a different color: red, white, blue, yellow or purple. These are also the colors that Pikmin come in.

Prankster Comets

Speedy Comet

Galaxy Episode Title Based on Time Limit
Good Egg Galaxy Dino Piranha Speed Run Dino Piranha 4:00
Space Junk Galaxy Pull Star Path Speed Run Pull Star Path 4:00
Dusty Dune Galaxy Sandblast Speed Run Blasting Through the Sand 4:30
Dreadnought Galaxy Topman Tribe Speed Run Revenge of the Topman Tribe 6:00

Daredevil Comet

  • The Daredevil Comet (デスコメット Death Comet) sets Mario's max health to only one unit, as opposed to the usual three (or six with a Life Mushroom). Additionally, it removes all Life Shrooms from the level so that Mario cannot get them. Five galaxies are visited by the Daredevil Comet; the Battlerock Galaxy, Ghostly Galaxy, Gusty Garden Galaxy, Deep Dark Galaxy, and Melty Molten Galaxy. Four of them have the player fight a previously fought boss, with the sole exception being Melty Molten Galaxy, which has the player complete the entire first mission (The Sinking Lava Spire) with only one health unit.

Cosmic Comet

  • The Cosmic Comet (シャドウコメット Shadow Comet) pits Mario in a race against Cosmic Mario in a predetermined course with a star at the end. Mario must beat his duplicate to the Star. Four galaxies are visited by the Cosmic Comet; the Honeyhive Galaxy, Freezeflame Galaxy, Gold Leaf Galaxy, and Sea Slide Galaxy. Hint: To get a head-start in front of Cosmic Mario, the player can hold forward on the Nunchuk, and when the timer reaches 2, press Z and Mario should turn yellow giving him an advantage. If the player is playing as Luigi, they will be racing against Cosmic Luigi instead. Unlike Cosmic Mario, Cosmic Luigi is more intelligent, and will take advantage of any shortcuts that are available.

Fast Foe Comet

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Mario crossing the Cyclone Stone in the Beach Bowl Galaxy.
  • The Fast-Foe Comet (クイックコメット Quick Comet) speeds up all enemies in a stage. Mario must complete the stage while avoiding the accelerated enemies. Only two galaxies are visited by the Fast-Foe Comet; the Beach Bowl Galaxy, and Toy Time Galaxy. Only Tox Boxes and Thwomps have been affected by this comet. The moving platforms also move faster. One familiar part is that it comes in galaxies with Toy boxes,which are the Beach Bowl and Toy Time only.

Purple Comet

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Mario approaching a Galaxy currently orbited by a Purple comet.
File:Purplecomet.jpg
Mario collects purple coins
  • The Purple Comet (パープルコメット Purple Comet) is only available after the main story is beaten. Purple Coins are hidden throughout the galaxy, and Mario must retrieve one hundred, sometimes within a time limit, to retrieve the Star. Some Purple Comet missions have more than one hundred Coins, but Mario still only needs to collect one hundred for the Star. All fifteen "main" galaxies are visited by the Purple Comet. Timed Purple Comet missions, as well as the Battlerock and Dreadnought Galaxy's Purple Comet missions have unique background music, which some of it is a remix of the Gusty Garden Galaxy music.
Galaxy Episode Title Purple Coins available Time limit
Good Egg Galaxy Purple Coin Omelet 100 None
Honeyhive Galaxy The Honeyhive's Purple Coins 100 None
Space Junk Galaxy Purple Coin Spacewalk 100 2:00
Battlerock Galaxy Purple Coins on the Battlerock 100 If Mario leaves a Coin, he loses a life.
Beach Bowl Galaxy Beachcombing for Purple Coins 100 None
Ghostly Galaxy Purple Coins in the Bone Pen 150 1:00
Gusty Garden Galaxy Purple Coins on the Puzzle Cube 150 2:30
Freezeflame Galaxy Purple Coins on the Summit 100 None
Dusty Dune Galaxy Purple Coins in the Desert 100 None
Gold Leaf Galaxy Purple Coins in the Woods 100 3:30
Sea Slide Galaxy Purple Coins by the Seaslide 100 None
Toy Time Galaxy Luigi's Purple Coins 150 3:00
Gateway Galaxy Gateway's Purple Coins 100 None
Deep Dark Galaxy Plunder the Purple Coins 100 None
Dreadnought Galaxy Battlestation's Purple Coins 100 If Mario leaves a Coin, he loses a life.
Melty Molten Galaxy Red-Hot Purple Coins 100 None
Grand Finale Galaxy The Star Festival 100 None