"Kitty" was an alien creature that fed on raw energy and was trapped inside a frozen comet to keep it dormant. In the episode "An Alien Affair" the Centurions accidentally released the alien when they attempted to explore the hollow interior of the comet.
Because it feeds on energy most of the Centurions weapons proved useless. Only Detonator's freeze-ray blasters were able to hurt it. The Centurions were able to imprison it, temporarily in a freezer but the Alien escaped and seized control of Sky Vault.
It was finally destroyed when Max Ray launched it out of the space station and on an intercept course with an orbital mirror. Unable to absorb the immense energy projected by the mirror the alien was destroyed.