Cranidos

Cranidos, quite frankly, hits about as hard as the comet that killed off its dinosaur brethren. Sporting an absolutely monstrous base 125 Attack equal to that of Gyarados all the way in OU, as well as a powerful STAB move in Head Smash, Cranidos is an offensive juggernaut to say the least. It also sports great coverage moves as well and an amazing ability in Mold Breaker. Combine this with good HP and decent Speed, and Cranidos has the potential to flatten unprepared teams.

However, not everything is peachy for Cranidos. Its Speed is only average, allowing faster Pokemon to prey on its mediocre defenses and take it out. Priority is also a thorn in Cranidos's side; most of the widely seen priority moves in Little Cup hit Cranidos super effectively, meaning that priority abusers probably need to be eliminated before Cranidos can be used effectively. Once most or all of the threats to Cranidos are gone, it can do what it does best: hit everything in sight as hard as possible.