Alien T-Rex

Alien T-Rex is a T-Rex-xenomorph hybrid that appeared in the film T-Rex vs Alien x Predator. He is one of T-Rex's recurring enemies.

Appearance
Alien T-Rex looks like the love child of a xenomorph and a T-Rex.

T-Rex vs Alien vs Predator
Alien T-Rex was created by Scientist Xenomorphs (just go with it) after they gained a sample of T-Rex's DNA when a really big xenomorph managed to pierce his skin. After some experimenting, they created Alien T-Rex, who would be their ultimate weapon against T-Rex and the Predators. Alien T-Rex was immediately unleashed by the Xenomorphs, rampaging and killing everything in sight. Little did the Xenomorphs realized that Alien T-Rex was far beyond their control. The combination of the two species caused the resulting creature to be completely insane and beyond any rational thought, simply killing everything in sight. After a long and brutal fight, T-Rex managed to defeat Alien T-Rex while the Xenomorphs and Predators all killed each other. However it was revealed ina cliffhanger at the end of the movie that Alien T-Rex had actually survived....

Moving to Earth.
Later on, Alien T-Rex somehow made his way to Earth. Apparently he had gained full sentience in between his first appearance and reaching Earth, and soon began to resume his rivalry with T-Rex, and the two fought each other a couple times. At some point, Alien T-Rex met up with Space T-Rex and the two became friends because they have so much in common.

Being in a Video Game
Alien T-Rex was approached to be in T-Rex Adventure, and ended up being a playable character, however only as an alternate skin of T-Rex/Evil T-Rex. In the story of the game, Alien T-Rex is a boss, and, alongside the other villainous T-Rex variants, later joined up with Evil T-Rex to do evil things. However of course at the end of the game the villains were defeated and Alien T-Rex escaped to parts unknown.

T-Rex: Final Final Wars: Giant Clusterf*** All Out Attack!
Alien T-Rex was in this somewhere because who the hell wasn't?

T-Rex Unleashed
Alien T-Rex was one of the playable characters in T-Rex, being a member of the bad guys from space faction.

Abilities

 * Same as T-Rex and a Xenomorph

Trivia

 * Originally Alien T-Rex was intended to be a parody of a lame Godzilla variant from a bad fanfiction called Alien Godzilla, and he still kind of is, but when I found a cool image he was somewhat modified and is now tied into the Alien franchise.