The Kitty Comet will appear on a very rare occurrence. There will be a massive meteor shower that will rain down kitty comets from space. While these comets cause a lot of damage, they also leave the rare Comet Kitty behind. Comet Kitties are black cats wearing space helmets, and have a tail like an ocelot.
The Kitty Comet event leaves floating black boxes in the air with peering green eyes on one side. They drop randomly during the meteor shower and leave an explosion similar to a charged Creeper's. Once the comets have dropped, in the midst of each of the explosions a Comet Kitty will emerge from the box and the box will disappear.
The comet can be very destructive of the environment and buildings. Considering that multiple meteors fall one after the other, a first one can destroy chests, and the following ones its contents.