AckStacks are enemies in Donkey Kong Country Returns. They appear in the fifth level of the Ruins, Itty Bitty Biters. AckStacks are brown sub-species of Toothberries. They appear in groups of five, piled on top of each other to form a wall. Just like how Gamygas can hardly be passed in Super Smash Bros. Brawl, AckStacks cannot be passed forcing the Kongs (Donkey Kong and Diddy Kong) to defeat them. However, if the Kongs force them to attack, they will back up, and try to fall on them with their mouths open, hurting the Kongs. The Kongs can pass them at this point. Like Toothberries, AckStacks, once they have fallen, take a jump to be defeated. However, the entire group of AckStacks are not defeated when one member of the AckStack is defeated; the Kongs must jump on all of them to get rid of them.