Predator

The Predator is a fictional extraterrestrial species featured in the Predator science-fiction franchise, characterised by its trophy hunting of other dangerous species for sport, including humans and its fictional counterparts, Aliens.

It made a cameo appearence in the Buffy/Angel crossover comic in the Wizard 1/2 magazine called "City Of" as a gladiator in the dimension both Buffy and Angel were trapped and set to fight, it´s very similar to