On the Rampardos (http://www.smogon.com/dp/pokemon/rampardos
) Trick Room set there is a small error to where I think the writer of that set confused Rhyperior with Rampdardos, although I could be wrong.
...Earthquake and Zen Headbutt hit most of the Pokémon that resist Head Smash for super-effective damage, other than Grounds, but Rhyperior has no real way of hitting those outside of Ice Beam. ...
So yeah, basically change it to "Rampardos" or "it" if it was supposed to refer to Rampardos and your good I guess. Hope that helped ^^.