TURF: Grasslands, Mountains.
CLOSE RELATIVES: None.
SKILLS AND ATTACKS: Brainless charge.
STRENGTHS: They can withstand two stomps. That is all.
WEAKNESSES: They are susceptible to everything, not too bright.
Rex is a Tyrannosaurus-like dinosaur, only much smaller. He's blue with
an orange belly, and he has tiny wings. They're not capable of flight.
Rexes are one of the regular inhabitants of Dinosaur Land, and probably didn't choose to assist Bowser. It is more likely that they was just trying to get a bite to eat, and foolishly thought that Mario looked tasty.