Iggy Koopa is one of the Koopalings.

Iggy acts as the first main boss of the game, being fought on the Derelict Airship in Yoshi's Island, similar to how he was the boss of the Jungle World in New Super Mario Bros Wii, like the other Koopalings, 3 jumps on his head defeats him, allowing Mario to continue to Rubble Ruins.