The "T-REX" is a MythicalPet introduced in the 12.5.3 update.
It appears as a small dinosaur with orange and light gray/white eyes, light gray ears, orange on the top of its head, a dark gray jaw with sharp teeth and the rest of the head is white. Its neck is orange, black and white. Its limbs are mostly black, except its wrists and ankles (which are orange) and its thighs, which are gray, white and orange. Its body and tail are generally white and light gray, but its front side is dark gray and orange. He also resembles kinda like of a robot.
The T-Rex deals terrifyingly high damage to armor-less or low level players making it a great starter pet.
Since the T-Rex is a Mythical pet you can use it to surprise unsuspecting enemies.
If you're a sniper, get this pet with strong armor so players behind you would be killed by the T-Rex.
Your T-Rex teleports to you when you are far away so you don't have to worry about it getting "lost" when you rocket jump.
Use the burning attribute as an advantage to burn players.
When it is maxed-up, it can 2 shot a max-armoured player.
Although this pet has much much more health then other pets, gunfire can easily eliminate it.
Kill it when using weapons with a high fire rate and great accuracy, such as the Champion Peacemaker.
Do not fight it in close range, as it can attack you and burn you, unless you manage to kill it in a distance before it attacks you.