Golon

Golon is the cruel dictator of Maru, known for his obsession with roundness. He swiftly punishes those who are not round (who he calls "ugly") by imprisoning them, forcing many of the planet's non-round citizens to don suits to appear round. Golon resembles a toad, and possesses both an ability to use its tongue like a toad and Samus Aran's stolen Morph Ball, which he keeps in a slot in his chest. Joey Apronika is brought to him for entertainment, but fails. Golon prepares to arrest him, but Samus intervenes. He then turns into a large sphere and begins bouncing off the walls, his attack power increasing with each bounce. Golon also possesses the Screw Attack, which he uses when close to Samus and Joey.

Trivia

 * In addition to resembling a toad, Golon resembles the Gorons of The Legend of Zelda series in his name, rolling ability and physical structure.