In Donkey Kong Country 2, they are quite rare. They only appear in a few select levels, and in those cases, there is a sort of Bonus Barrel that can be found utilizing the invincibility. Any enemies who make contact with a Kong while invincible is be defeated. In Donkey Kong 64, the Donkey Kong Barrel have a similar function, but only Donkey Kong can use it (for reasons that are left unspecified).