In its original form, Hypnos-T Type resembled a genderless and hairless youth with smooth white skin. The only visible mutations were confined to one arm, which was discolored and slightly larger than the opposite limb, its fingers also ended in small claws that could be used for stabbing attacks.
In the second form, the Tyrant's mutations became more prominent, with a mouthful of fangs and much larger claws on its larger arm. Its muscle mass increased slightly, most notably on the upper body and left arm, with a visible bulge where the heart was beginning to expand. In this state, Hypnos could run at high speeds and viciously slash its opponents. It could also perform a downward strike. Its most dangerous attack was a powerful jumping strike performed at a distance.
In its final form, Hypnos-T Type suffered through a form of hypertonia, becoming a bestial, hunched, primate-like monster. Because of the excessive muscle growth, the Tyrant was rendered vulnerable, with the heart becoming exposed as is common in its brethren; it also lost much of its intelligence, rendering it little more than a wild animal. These new weaknesses didn't make it any less agile, however, and it was able to protect the exposed heart by shielding it with its claws.