The Koopa Kids are minions of Bowser who have only appeared in the Mario Party series. They are known as Mini-Bowsers in PAL territories, Mini Koopa in Japan (Bowser's name in Japan is Koopa) and Baby Bowsers in Mario Parties 1, 2, and 3. The Koopa Kids resemble miniature versions of Bowser (and are therefore very similar in appearance to Bowser Jr. and Baby Bowser). Originally, the Koopa Kids were nothing more than minions indirectly fought by the Mario crew when the Koopas attempted to crash their parties, but in Mario Party 5, one was finally made playable (despite this, Bowser shows them no mercy when they land on his space. This is obviously so players using Koopa Kid do not have an advantage).
It is unknown how many Koopa Kids there are. Originally, there seemed to be only a few, but Mario Party Advance implied there may be hundreds of them.
Mario Party 5 also introduced Green K. Kid, Red K. Kid and Blue K. Kid who, as their names imply, are colored differently. The aforementioned colored kids are one Koopa Kid split into three. It is unknown if other Koopa Kids are also capable of duplicating like this.
Koopa Kid's future is uncertain, as he does not appear in any games following Mario Party 7. Additionally, Bowser Jr. has started appearing in the Mario Party series since Mario Party DS, implying that Koopa Kid may have been retired in favor of him.
 Mario Party
The Koopa Kids made their debut appearance in the original Mario Party, as Bowser's henchmen, however despite being his henchmen, they are not seen until the end of the game.
After beating Bowser's board, Bowser will steal all the stars that the player collected throughout the game. Next he travels to the Eternal Star board, where he sets up base until the players find him, but before they can get the stars back, Bowser summons a group of seven Koopa Kids and forces the players to challenge them to the board.
When the players challenge the Koopa Kids, they must play the same way they did with their previous opponents, but this time if the players get close to a Koopa Kid they must challenge them to a mini game. The mini game involves jumping underneath a numbered block and the key to winning the game is whether the player selects a higher number than their opponent.
Following success and defeating the original group of Koopa Kids, a new group appears and the player must start all over again. Once the new group is defeated, the board is won and the players will use their stars to beat Bowser. Eventually the Koopa Kids and Bowser are sent flying into the air.
 Mario Party 2
In Mario Party 2, the Koopa Kids appear on every every board in the game, where they often cause trouble for the players. The things that they do to the players whenever they land by them are, stealing their coins and items, giving them worthless things, making them land on bad spaces and finally knocking them into random spots. They often annoy Toad too. Despite them annoying the players, they do help them at times, but that is only if they're doing bad and although they do this stuff to players they don't have a very significant role. Even though they didn't have an important role on the previous boards, the Koopa Kids appear a lot of times in Bowser Land, where one of them replaces Toad as the host of the board.He gives the players advice although sometimes they're just lies in order to make them lose, another one was also seen later on the board where he appeared to be the leader of the Bowser Parade, during it he will stand behind the player who decided to go on it and then it will keep going on for a while until he has it come to a complete stop.There is also another place in Bowser Land which has a Koopa Kid and that place is called The Bowser Bank. There the Koopa Kid this time known as the Koopa Kid Banker will trade any amount of coins to the player in exchange for 20 coins but if the players don't have enough coins then the Koopa Kid Banker will send them back to where they started. Interestingly unlike the other Koopa Kids who are the same colour as Bowser the Koopa Kid Banker is blue and wears glasses, he also resembles Blue K Kid who is one of the Koopa Kids who appears in later games of the Series. Lastly there is an item shop in Bowser Land that is owned by a Koopa Kid here he will forcibly give the players any random item he has and you do not know if its useful or useless but mostly it turns out to be useless showing as when the players use it, it only ends up doing damage to them.
 Mario Party 3
In Mario Party 3, Koopa Kid ran his own Item Shop, which sometimes appeared in place of Toad's, where he sold sneaky items such as Lucky Lamps, Reverse Mushrooms and Boo Bells. Koopa Kids also appeared in the Item Minigame, where they often symbolized losing, such as the Koopa Kid space in Winner's Wheel.
In Duel Mode, Koopa Kid also appears as one of the possible partners. He isn't a default partner, but can be obtained through the lottery. His attack is one, and his health is one. He can occasionally turn into Bowser and deal triple damage when attacking; however, if the transformation fails, he deals no damage. Koopa Kid's salary is three coins per turn.
 Mario Party 4
In Mario Party 4, a Koopa Kid would usually come in place of Bowser whenever someone landed on a Bowser Space, and would steal Coins from either the player who landed there, or from all the players. Sometimes, the Koopa Kid would then call Bowser after stealing coins, and a Bowser event would begin. In the Bowser Minigames, two Koopa Kids worked as Bowser's servants; one of which was seen fanning him and the other one explains the rules to the game (which may be Fruits of Doom, Darts of Doom or Balloon of Doom) and in addition, he also brings the dart board to the players and announce the scores in Darts of Doom. One also hosted the last board: Bowser's Gnarly Party and could be seen selling items and hosting board games. In addition, Koopa Kid can be unlocked in the volleyball minigame.
 Mario Party 5
Mario Party 5 marked the first time Koopa Kid could be played, but not in the Story Mode. In the Story Mode, Koopa Kid split up into Red K. Kid, Blue K. Kid and Green K. Kid, and the player had to steal all their coins on abridged versions of the regular boards to defeat them. In Card Party, Koopa Kid shows up to cause trouble on the Bowser Card. In the PAL version of Mario Party 5, they were called Mini Bowser, Red M. Bowser, Blue M. Bowser and Green M. Bowser.
 Mario Party 6
In Mario Party 6, Koopa Kid retained a role similar to that in 5, except that Red K. Kid, Blue K. Kid and Green K. Kid were the rivals in the Solo Mode, and the goal was not to defeat them. Rather, they just served as opponents during Minigames.
 Mario Party 7
In Mario Party 7, Koopa Kid was no longer playable. Instead, he appeared whenever someone landed on a Koopa Kid Space, and would do things such as swapping players' coins or positions, or use a Cursed Mushroom on the player/team who landed on his space. Red K. Kid, Blue K. Kid and Green K. Kid were also the main antagonists in the three multiplayer Bowser minigames, and operated the cannons in Bowser's Enchanted Inferno!.
 Mario Party Advance
In Mario Party Advance, Koopa Kids could be seen working with Bowser, and appeared in some of his minigames, where the object was usually for the player to defeat them. Up to ninety-nine of them could appear at once. One main Koopa Kid appears throughout the game as Bowser's right-hand man, often appearing to antagonize the player by doing things such as stealing Mushrooms from them or flinging them somewhere else on the Board Map.
In Mario Party 4, whenever a Koopa Kid calls for Bowser, he refers to him as "Dad". However, it is unlikely that Bowser is the biological father of all the Koopa Kids, and that the Koopa Kids may just be clones of some nature. Bowser's real son is most likely Bowser Jr. Similarly, Bowser also grounds them by taking away their Mario action figure if they fail him, hinting that Bowser at the very least has a father-like relationship with them. It's possible that Koopa Kid has a teacher-student relationship with Bowser since he calls him "Mr. Bowser". While the small Koopa shows a lot of loyalty to Bowser, he also takes the side of Mario and company every once in a while, as evidenced in Mario Parties 5 and 6. It is also likely that Koopa Kid works for Bowser for money, due to him telling himself, "I bet Mr. Bowser will totally give me a raise after this!" However, when the player plays as Koopa Kid in Mario Party 5 and Mario Party 6, Bowser doesn't hold out when he lands on a Bowser Space, indicating Bowser may not like Koopa Kid or it is just because of the game mechanics.
 Character Artwork
 List of Appearances by Date