Bowser's bogus items
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 does not sell the player an item, but instead provides them with some worthless "service."
Bowser forces the player to buy a Ztar. 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, making it the most expensive of the bogus items. It should be noted, though, that immediately after buying the Ztar, the player will pass Koopa Troopa and earn back 10 coins (20 in the last 5 turns).
Luigi's Engine Room: "Make As Many Coins As You Want Mecha"
Bowser activates his "Make As Many Coins As You Want Mecha" in order to create a coin for the player at the cost of 20 coins, thus meaning the player loses 19 coins, due to the one coin they get from the machine.
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 board game). The player will pay 10 coins for the ride.
Yoshi's Tropical Island: Bowser Tube
Bowser creates an inner tube that he says will allow the player to help the Yoshi and travel over the whirlpools. However, upon being put on the player, the inner tube shrinks and then bursts around the player. Bowser demands 30 coins for buying (and in this case, popping) his merchandise, making it the second most expensive bogus item.
DK's Jungle Adventure: Gold-plated Bowser Statue
Bowser sells this item to players for 10 coins on DK's Jungle Adventure. It looks like a miniature version of the Koopa King, and is completely worthless. A version of this statue also appears in Mario Party 6 and Mario Party 7.