Rex

Rexes are dinosaur-like dragons who inhabit Dinosaur Land and other places, first appearing in Super Mario World. Their name is a reference to the predatory dinosaur Tyrannosaurus rex. They are purple with single horns on their noses, fangs, and small dragon wings with which they can fly. They also wear big red shoes, similar to Yoshi.

Non-fanon history

 * 1) In 1990, Rexes were merely inhabitants of Dinosaur Land and couldn't care less about attacking Mario, Luigi, and Yoshi.
 * 2) In 2003, some Rexes were spotted living on Hoohoo Mountain. These Rexes are active attackers if provoked and are resistant to fire. In fact, fire heals them.
 * 3) In 2005/2006, it was discovered that Rexes can be seen living on Vibe Island. Some have the Sad Vibe, causing them to often stay still, moping, unless someone gets too close to them, in which case the Sad Rex will start charging through.

Bowser the Warrior
Rexes can be found starting from Stage 4. In this game, Rexes walk left and right in a fixed pattern, but can suddenly jump high between a fixed interval.