Donkey Kong Country/Levels/Necky's Revenge
This boss should remind you of the world 2 boss, Necky's Nuts, now his dad's here! He's angry and you can tell because he's...purple. You defeat him in exactly the same way, wait for him to appear and jump on his head. The main difference in this fight though, is that after the first hit, he'll shoot 2 nuts... after second hit, 3 nuts, and so on. Necky Sr. attacks you in the same way otherwise. Just keep jumping on the purple Necky's head to win a Giant Banana.