The title of this article is conjectural; an official name for the article's subject has not been found, so it has been given a fitting title by the editors. If an official name is found, then the article should be moved to its appropriate title.
Bowser's Bogus Items are useless items forcibly sold to partiers by Bowser in Mario Party when they pass him on a board. On Luigi's Engine Room and Wario's Battle Canyon, he doesn't actually sell the player an item, but instead provides him or her with some worthless "service." The items are:
Mario's Rainbow Castle: Ztar
Bowser forces the player to buy a Ztar. It should be noted that unlike Ztars later in the Mario Party series, this one does not count as a negative star. However, the Ztar costs 40 coins as opposed to a regular Star costing 20 coins.
Luigi's Engine Room: "Make As Many Coins As You Want Mecha"
Bowser activates his "Make As Many Coins As You Want Mecha" to create a coin for the player at the cost of 20 coins.
Peach's Birthday Cake: Bowser Cake
The player can obtain this item when playing on Peach's Birthday Cake. When a player "wins" the Goomba lottery, they are sent to Bowser, and he forcibly gives the player this item for 20 coins. It is just a spiked shell with a candle and frosting, and cannot be eaten.
Wario's Battle Canyon: Bowser's Claws
He says he will shoot the player from his Bowser Cannon, but instead uses his claws to blast the player to a random area of the board (ironically, the cannon itself is never fired until the end of the game).
Yoshi's Tropical Island: Bowser Tube
This item was obtained on the tropical map, Yoshi's Tropical Island, where a Yoshi was stranded on a tiny island surrounded by whirlpools. Seeing this, Bowser created an inner tube that he said would allow the user to help the Yoshi and travel over the whirlpools. However, upon being put on, the inner tube would shrink and eventually burst around the player. Bowser would then demand 30 coins for buying (and popping) his merchandise. The tube is Bowser's second-most expensive Bogus Item in the game, the most being the Shadow Star of Mario's Rainbow Castle.
DK's Jungle Adventure: Golden Bowser Statuette
Bowser sells this item to players for 10 coins on DK's Jungle Adventure. It looks like a deformed version of the Koopa King, and is completely worthless. A giant version of this item was seen in the Mini-Game called Seer Terror from Mario Party 6. If players received the statue, it dropped right on top of them. Its true second appearance was in Mario Party 7, where Bowser sold it to players for 20 coins, then Koopa Kid took it away.