Also known as the Koopalings, these seven twerps are Bowser's supposed children. Several of them appear as mini-bosses in the game, though a few are seen minding their own business in the World Gallery. They're all on this trip with Bowser, but adult supervision isn't his thing. In order of appearance...
The smallest of the Koopa Kids is in the first gallery, alone and lost. Larry was supposed to be watching out for him, but he ran off someplace leaving Lemmy totally stumped. The Koopas have such a close family.
As it turns out, Larry didn't go too far from Lemmy. He's in the Gallery 1 mini-boss portrait, The Port of Adia. Koopa Kids have always had an affinity for ships since the days of SMB3, so he's right at home in the harbor.
One of Bowser's heavier kids is hanging out in the basement gallery. He's not causing any trouble, but he's sure his brother Iggy is. Maybe he just likes dank places, but his darker skin and shell sure blend in nicely.
Bored with all this art crap, Iggy ran off to raid the desert with a gang of Shy Guys. They put him in charge of the explosives, which he's more than happy to hurl every which way.
Bowser's other tubby turtle is partway up the lofty 6th gallery. He's upset that Wendy gave the trip a pass, but he totally understands. When you get a once-in-a-lifetime opportunity, a musty castle full of art isn't going anywhere.
Wendy O. KoopaEdit
When given the choice between a boring museum and hanging out with a Koopa pop star, the choice is clear for a lady of Wendy's caliber. The only thing fancier than her looks is her footwork on the dance floor.
Ludwig von KoopaEdit
Much preferring music over art, Ludwig found little of interest in the World Gallery. It only served to remind him he'd rather be in his own castle somewhere. Luckily, he found Castle Crushers unoccupied and got in there before his dad could.