Great One

The Great One is a giant, tick-like alien that travels from world to world, sucking the energy from the planets it lands on to feed itself. This process poisons and eventually makes the worlds it visits implode. Its shell is nearly impenetrable and its feeding process brings the ground to life as an extra defense, making it very difficult to attack. On top of that, it is followed by a group of The Great One's worshipers that want to make sure that it completes its task. The Great One is destroyed from the inside by Ben as Cannonbolt. The Great One is responsible for the complete destruction of Cannonbolt'shome planet about a week before it tried to destroy Earth, a somewhat ironic accomplishment considering its death at the hands of a member of the same species (albeit a spliced version).