Solid Rock is its ability obviously. This was the second Rhyperior because te first had LightningRod (that guy is still in my PC, nobody wants a LightningRod Rhyperior. Plus, he is there for memories. That guy has Rock Wrecker.) Rhyperior can either be defensive or Offensive. I choose for mine offensive because that is what I am. My good Rhyperior, the one who I sometimes use, knows:
Stone Edge: High power, good chance for a critical hit, STAB, type coverage. Used to deal with Ice types.
Earthquake: From here on, I'm not going to list reasons for this move.
Megahorn: High power, used to deal with Grass types.
Avalanche: Deals with Ground types and Grass types, high accuracy and usually high power, otherwise decent power. Works well because Rhyperior is SLOOOOOW. Also deals with the ever popular Dragon type.