The main variation between this Tyrant and other models was the inclusion in its genetic makeup of the Hypnos gene, a modified genetic strand that, when implanted into an organism, would kill the weaker cells through natural selection, leaving only the best to keep the organism ongoing and encouraging the reproduction of the better cells. This gene was created by Sheena Island Umbrella scientist Doctor Klein.
When first seen, the Hypnos Tyrant resembled a genderless, hairless youth with claws for digits, floating in a stasis tank. Once awake, it proceeded to kill one of three people according to the selected scenario: Andy Holland, the sewer janitor, Vincent Goldman, the Umbrella Commander of Sheena Island, or the UT (Umbrella Trashsweeper or UnderTakers) commander. After minutes of fighting against Ark Thompson, the creature mutated into a more aggressive second form, with greater muscles, much larger digits upon its left claw and an enlarged mandible. After a while, however, the Tyrant mutated again.
This final mutation was more of a regression than true evolution, as the beast lost much of its intelligence in the process, suffering through a form of hypertonia, losing its humanoid shape and becoming a bestial, primate-like, hunched monster. Because of the excessive muscle growth, the beast was rendered vulnerable, along with a fissure in its integument covering its right pectoral. This Tyrant model was destroyed when it leapt upon Thompson's escape helicopter, at which point a missile was launched into its abdomen. Seconds later, another missile was launched against it. It is extremely unlikely that it survived the two blasts.