It puts rocks in holes in its palms and uses its muscles to shoot them. Geodude are shot at rare times.
Rhyperior is a large, brownish-gray Pokémon with two horns: one on its nose, and another one above it. The upper horn is smaller on a female Rhyperior. It has a club-like tail and its hide is partially covered by orange, rocky plates. It has blade-like protrusions on its elbows and has holes in the palms of its hands which works as a cannon or a gun. Rhyperior can insert rocks and boulders into its arms through the holes in its hands and then fire them like bullets. However, it will occasionally insert and fire Geodude by accident. It also appears to have two thick, rectangular rocks above its eyes, resembling heavy eyebrows. Rhyperior lives far up in the mountains.
(From Bulbapedia)Its design appears to be an amalgam drawing inspiration from a rhinoceros, aspects of various dinosaurs (such as ceratopsids or Ankylosaurus in particular), bullet-resistant body armor vests, as well as cannon artillery. Its overall appearance also seems to allude to a proverbial miner sporting a mining drill, safety vest, and hard hat.
(From Bulbapedia)Rhyperior is a combination of rhinoceros and superior. Rhy may also derive from the igneous rock called rhyolite, alluding to Rhyperior's Ground/Rock type combination.