Rex is a character owned by Tree Fortress Games and makes a cameo in Indie Pogo. He appears in the game JumpJet Rex.
"Rex is a Dinonaur who loves 3 things: Speed. Style. Shiny Trinkets. When he straps on his trademark JumpJet boots, he is able to defy gravity by endlessly jumping. This is exceptionally useful in his misssion to save earth from an incoming asteroid." ― Rex's Trophy Description.
Rex comes from the game JumpJet Rex, where the player plays as a Tyrannosaurus equipped with jet-propelled boots which give them the ability to hover, dash, and boost.