From the Super Mario Wiki
Fireballs are enemies that appear in the Wii game, Donkey Kong Country Returns and its 3DS remake Donkey Kong Country Returns 3D. They are a variant of Tiki Zings drenched in fire, and relatives of Big Zings. Fireballs appear only in the Cliff level, Precarious Plateau. Even though Rambi is able to defeat Tiki Zings, he cannot defeat fireballs. If one of the Kongs make contact with these enemies, they will lose a life immediately. They have seven razor blades and a sinister face. Like their Tiki Zing relatives, fireballs move around, trying to block Donkey Kong's path.