Regirock is a light grey, tan and orange Pokémon with seven little orange dots on its head that resemble a face. It has two huge orange boulders on its shoulders and there is one rock right under its face that is orange, another orange one by its ankle and three spiky ones on its back. The rest of its body is a light tan, and it's whole body appears to be made of many separate rocks with cracks between them.
Regirock made its first appearance as one of Pyramid King Brandon's powerful Pokémon as he battled against the King of Pokélantis who possesses Ash in an unofficial battle. Later on he battles Brandon from the second time to acquired the Brave Symbol as he uses Regirock to face him. Unfortunately, Ash lost the battle and had to challenge him again until he gains the Brave Symbol due to Brandon uses Ninjask, Solrock, Dusclops and his new Pokémon Regice to face Ash in a 4 on 4 battle to know more of Ash's four of his old Pokémon. The Pokémon also made an appearance in Lucario and the Mystery of Mewas one of the three guardians of the Tree of Beginning, along with Regice and Registeel.
In the Diamond and Pearl series, Brandon uses Regirock, Registeel and Regice respectively to face off against Paul in a three on six battle and later against Hunter J who is responsible for awakening Regigigas in a rage as well as mind controlling all of his Pokémon.
Regirock is the only one of the Regi Trio that does not have fingers.
Regirock is the only one of the Regi Trio to show a letter on its eyes. The letter on Regirock's eyes is H.
Like the other Regis, Regirock is weak to Fighting-type moves.