Omastar

Omastar's typing is almost unique in OU, being shared only with Kabutops. It provides it with useful resistances to Normal and Ice, which allow it to punish Hyper Beam and Explosion, and let it check Snorlax and Tauros lacking Earthquake. This is backed up by its solid bulk and good Special, which enables it to do significant damage with Hydro Pump. Its movepool contains decent utility and coverage options such as Ice Beam, Seismic Toss, Submission, and Body Slam.

Omastar is not recommended for most OU teams, though, as it is plagued by several crippling flaws that outweigh these qualities. It is walled by the omnipresent Chansey and the common Starmie. Slowbro also has little trouble walling it and can use it as an opportunity to set up with Amnesia. Omastar's typing is a double-edged sword that gives it weaknesses to Earthquake and Thunderbolt, which are both common in the metagame. Even if it avoids both, Omastar has to rely on Rest for recovery, which renders it useless for two turns, giving offensive threats such as Tauros and Zapdos opportunities to switch into it and wreak havoc.