Rex

Appearance
Rex looks like a dinosaur or a dragon with fangs and small wings portruding from it's shoulders. It almost resembles yoshi in fact.

Methods to stomp
When stomped once, a rex will shrink and have a squashed apperance. He will also run faster. In order to

defeat Rex, you can either stomp on him twice, Spin jump to take him out in one Shot or use fireballs.

Other apperances
Rex appears in several mario RPG's including partners in time (in which he appears in a shroob form), Superstar Saga and Super princess peach.