Koopa Troopa (Mario Party 4)
Prior to the game's events, Koopa Troopa, along with the other hosts, came across a large cube in a Warp Pipe. They carve out images of themselves on the cube and, once they finish, the cube suddenly grows to a much larger size. The five then decide to host a party and fill an envelope with party invitations for Mario and his friends. They send the envelope with Lakitu to Mario before getting atop the Party Cube. In the game's intro, the five appear before Mario and his friends, formally inviting them to their party.
In the game's story mode, Koopa Troopa offers the player character a present should they beat his board. However, upon doing so, Koopa Troopa reveals they must also beat him in his minigame, Kareening Koopas. Once the player beats him, he gives them their present, which is a Matryoshka doll of that character.
On the surface, Koopa Troopa appears to be a laid-back type of character and loves the idea of a beach resort. He dresses as such, wearing a light blue colored shirt with a tropical design. He appears friendly and sociable to the player characters. However, the Prima guide for Mario Party 4 states that he is only interested in gaining money for his resort and that his motives are purely selfish. This could possibly reference the bank Koopa Troopas in Mario Party 2 and Mario Party 3, a reference furthered by the Koopa Troopa who runs the Koopa Kabana.