The Big Tick

During a trip to Yellowstone National Park, Ben discovers the eleventh alien on the Omnitrix, Cannonbolt. At the same time, a meteor crashes nearby unleashing a giant, tick-like alien called the “Great One” that intends to devour Earth. Ben easily defeats the worshippers, but the Great One turns out to be impervious to the original ten aliens. Ben quickly discovers that Cannonbolt is impervious from any attack when rolled into an armored ball and penetrates the Great One’s armor in that form, killing the alien from the inside.