Rainbow tarax

This reptile, a dinosaur still living in {}, has the peculiarity of having a rainbow coloured iris. Alive, this eye allows it to cast color-themed spells. Dead, it allows its wielder to defend once against those very same spells.
Physically, it looks like a mix between a Velociraptor and a T-rex. While it is usually carnivorous, it will greatly prefer eggs to meat if given the opportunity.
Regarding its behaviour, one could compare it to an assassin's tactics. The rainbow tarax will sneak up on its target, then blinds it with its natural casting if needed before attempting to strike a vital point. Its "hands", outfitted with a sharp edge on the articulation between the articulation of the middle of the thumb and the head of the radius, allows for particularly efficient sneak attacks. All of this makes for a terrifyingly efficient hunter.