Ack

Acks are red enemies with sharp teeth that first appeared in Donkey Kong Country Returns. They are found in the fifth level in the Ruins world, Itty Bitty Biters. They are related to Toothberries, AckStacks and Cageberries. Acks are more aggressive and bigger than normal Toothberries. They also require two jumps to be defeated, while Toothberries only require one. Alternatively, a Kong Roll will take one out with one hit. To attack the Kongs, Acks attempt to jump on them. Their jump is the highest out of all their relatives. If Donkey Kong and Diddy Kong make contact with these biters, they will lose a heart.

AckStacks are yellow Acks that appear as a tower and attack as a group.