

Back stateside, Ben can't get into a cat cosplay competition, Top Tail, without a cat costume of his own; but when he goes Rath, a new cat-like alien with an attitude, Ben's newfound wild side quickly becomes much more than he bargained for, and must learn to hold in his rage.
When Grandpa Max’s engineer buddy Phil Billings gifts Team Tennyson the Omni-Copter, a state of the art flying vehicle that can transport the Rustbucket for overseas adventures, Steam Smythe takes to the skies to ground Ben and company’s first test flight; but unbeknownst to our heroes, Smythe was sent to battle Ben’s latest alien forms by a mysterious, powerful enemy: the Forever Knight.
During one last stop by a toy store before Ben, Gwen, and Grandpa Max's maiden voyage across the Atlantic, Ben runs into an old bully, Kevin 11, who now has new powers. He's able to transform into aliens just like Ben, such as the "bootleg" doppelganger of Cannon-bolt—Wrecking-bolt!