Regirock is a large golem-like Pokémon made of brown and orange rocks and it has a pattern of seven orange dots on its face that resembles a capital letter "H". It has long arms with jutting shoulders and club-like hands without fingers. There is a line of orange rocky spines running down its back and its legs are short in comparison to its body. When it gets damaged in battle it will search for new rocks to repair itself. Because of this, the rocks it is made of come from several different places, which contributes to Regirock's patchwork appearance. Recently, cutting edge technology has found that Regirock is entirely made of stone and rock as it does not seem to have a heart or brain. It generally lives in caves or ruins as it was sealed away years ago by ancient people.
Regirock debuted alongside the other members of its trio in Lucario and the Mystery of Mew. It is a guardian of the Tree of Beginning, and it was the first to attack perceived intruders Ash and his friends. In the end, Regirock and the other guardians realized they were not a danger and kept on with protecting the Tree of Beginning.
Regirock was Brandon's first Pokémon during his battle with Emerald, where it found Sceptile's Leech Seed attack to be of minor annoyance and knocked it out right away with its Explosion attack. However, while the Pyramid King's attention was focused on Jirachi's light coming from the horizon, Emerald was able to revitalize the fainted Sceptile with a Revive and win the battle.
In the international versions of Ruby, Sapphire, and Emerald, there is an unobtainable Regirock Doll programmed into the game. It was unlockable with the Japan-exclusive Regi-Dolls Decoration sete-Reader card.
Regirock's base Attack and Special Attack, as well as Defense and Special Defense, are reverse of Regice's.
Regirock may be based on the golems of Hebrew legend. The legends cast them as servants of higher powers and are said to have writing on their heads. When the writing is removed, the creature would be weakened, or even killed in some legends.
The five Legendary titans may be collectively themed after historical epochs, with Regirock representing the Stone Age.
Regirock is a combination of regis (Latin for royal) and rock.