Hariyama (M) @ Toxic Orb
EVs: 252 HP / 252 ATK / 4 SDEF
Adamant Nature (+ATK, -S.ATK)
-Close Combat: (STAB) High Power and reliable
-Bulk Up: Help boost the already incredible attack stat and boost your defense as well.
-HP Dark/Payback: HP Dark to keep them guessing if you're bug or ghost or dark, and Payback just to deal 2x damage to Psychic types
-Ice Punch: To deal with pesky flying types
Since I'm running mine on a trick room set payback isn't of much use so that's why I chose HP Dark over payback.