Ultra Super Saiyan is a form that attains more power than that of a regular Super Saiyan. It is attained through difficult and extensive training as a regular Super Saiyan. Both Goku and Future Trunks are shown in the anime achieving this form. As far as appearance goes, as an Ultra Super Saiyan both Goku and Trunks attain colossal muscles. Their hair also becomes more pointed and extends in a multitude of directions. Once Goku achieves this form he quickly realizes its detrimental downside. His muscles have become so large that is makes it extremely difficult for him to move, thus significantly decreasing his overall speed. Although Trunks on the other hand fails to realize the major flaw, and decides to challenge Perfect Cell in the state. It is not only after suffering a beating from Cell, does Trunks realize is speed is not nearly up to par with that of his adversary.