Roy Koopa

He's big and he certainly comes in handy when you want to toss around a few toads you meet along the lane. He's a tough Koopa, and while he might not be the brains of the Koopa Klan, he knows everything there is to know about how to make you hurt. Roy is, actually, very loyal to his father and the magnanimous Koopa Troop... or at least as loyal as a power-grubbing evil Bowser spawn can be. He's definitely the sort of Koopa you'd be best to keep on good terms with.

Super Mario Bros. 3
Roy Koopa is so heavy so that he caused smaller earthquakes when he jumped. These quakes stunned Mario and Luigi for some seconds leaving them defenseless.

Super Mario World
Roy attacks Mario in a small closed room. First he tries to charge over him and then walks up the walls and then continue up-side-down in the top of the room in the ceiling. When Roy is directly above Mario he loses his grip and tries to fall down on him.

Yoshi's Safari
He guards course 7, the Float Castle 1. Roy attacks Mario and Yoshi from high up in the air in an balloon equipped with no less than 6 cannons.