Tyrantrum is a massive bipedal dinosaur-like Pokémon that resembles a Tyrannosaurus Rex. It has craggy auburn rock-like scales covering most of its body, while its underbelly is gray and white. It has a large spiny white fringe around its neck. It has small arms with two sharp black claws, and powerfully-built legs. Its feet are very large with three sharp black claws on each. It has many sharp white teeth on its lower jaw, and craggy red fangs on its upper jaw. Tyrantrum has an orange spiked crest on its forehead, and small white eyes. It has a thick, powerful tail with orange spiked formations at the tip.
Tyrantrum evolves from Tyrunt at Level 39 during the day.