The Little Rex is a Dark Gaia Minion that appears in Sonic Unleashed. These diminutive creatures resemble a cross between a bulldog and a tyrannosaurus, and like all Dark Gaia monsters emit a cloud of purple vapour from their bodies.
The Little Rexes are able to move around by either teleporting into an area in a puff of purple smoke, or emerging from black puddles on the ground. As a Dark Gaia minion, the Little Rexes can possess people by latching onto the deepest, darkest part of the heart, and generate despair, negative emotions or even erratic behaviour that are completely opposite to the person's personality.
Despite their size, the Little Rexes are rather fast on their feet, allowing them to easily keep up with Sonic the Werehog's normal running style. They also have powerful jaws, giving them a nasty bite, though their bites hardly cause much damage to the Werehog.