Waybig is a To'kustar, an enormous alien, nearly 100 feet tall, and by far the biggest alien in Ben's arsenal. His appearance is somewhat reminiscent of tokusatsu superheroes, particularly those of the Ultra Series. Waybig's size grants him extraordinary strength and invulnerability to most attacks; however, in proportion to his size, Waybig does not seem to be any more durable than normal, as Vilgax is able to cause him pain by digging into Waybig's hand with his sharp claws. Waybig first appears in Ben 10: Secret of the Omnitrix, when Azmuth activates it on the Omnitrix so Ben can fight off Vilgax's army. His only appearance in the TV series itself was in "Ken 10" when Ben loses his temper and mercilessly pummels Kevin into the ground after the latter pushes him too far by injuring Ken.
In the Ben 10 Season 4 DVD, it was revealed in the Special Trivia Edition that Waybig has no home planet, they are simply created during unpredicatble cosmic storms.