Koopa Kid are minions of Bowser who only appear in the Mario Party series. They are called Minikoopa or Mini Koopa in Japan (Bowser's name in Japan is Koopa), Mini Bowser in Europe, and Baby Bowser in Mario Party 1 through 3. The Koopa Kids resemble miniature versions of Bowser (and are therefore very similar in appearance to Bowser Jr. and Baby Bowser). A Koopa Kid also appears as a playable character in Mario Party 5 and Mario Party 6.
In the earlier games in the series, there appears to be an arbitrarily large number of Koopa Kids, as shown by minigames such as the Mario Party 3 mini-game Baby Bowser Bonkers. Indeed, Mario Party 4 specifically refers to the Koopa Kid who appears on Bowser Spaces as "one of the Koopa Kids". However, starting in Mario Party 5, there seems to be only a single Koopa Kid, likely due to his new playable status. However, more than one can appear at once in Mario Party 7 (where Koopa Kid is non-playable again) in Pyramid Park.
Koopa Kid appears to have been retired, as he has not made a major appearance in any game since Mario Party 7 in 2005. His only appearances since then are as a sticker in Super Smash Bros. Brawl and as a brief cameo in Mario Party: The Top 100 on boxarts of previous games.
Not much is known about Koopa Kid's personality, as he does not get much development and changes his behaviour up constantly.
Koopa Kid appears to enjoy causing mischief, as seen in Mario Party 2, where he sometimes tricks Mario and company into thinking that he is Toad, or Mario Party 7, where he can cause a variety of antics such as switching everybody's positions on the board. It appears that he is not meant to be taken too seriously, as he comments in the latter game that he attempts to make the players' lives "miserable" by doing petty things. However, he does play fair and square, giving away stars when he is beaten in Mario Party. and selling legitimate items in Mario Party 3 and 4. He seems to be friendly towards Mario and company, especially Brighton and Twila.
- Princess Peach
- Princess Daisy
- Donkey Kong