If it's a tek rex, T-800
Rex

Name ideas for your Rex from ARK players.
Tyranitar
Thunderjaw
Titanspoken
Tyrantrum
Ares
Tyrannosaurus Flex
Discount Dodo
Rexy (for females only! Jurassic Park)
Darth tyrannus
Big Eatie.
Gobbles (from gameoverse)
Tina Amazing world of Gumball anyone?
Grimlock
Hippity _hoppity_ur_life_is_my_property
Very Normal Dodo
FedRex
Baby giga. Alpha compy.
Wrex it Ralph
Sharptooth
Buck (of Jurassic World/Park)
Brexfast
“Doe”
RKER (Random kill everyone)