Steelix is a lustrous, silvery gray snake. They are about 30 feet long. Their body is made up of rock-like sections, three of which have massive rock spikes coming out of them. They have a massive head mainly made up of their jaw. The jaw is large and wide with sets of large square teeth inside. Along their bottom jaw are a pair of ridges (varies with gender). Their eye sockets are slightly set in, giving them good eye protection. Underneath their bottom jaw there are small square domes. Their heads have two long ridges going from the eyes up to the top of their heads. Their jaws also have massive ridges where they meet their skull. Their tail ends in a long sharp point, but with a blunt tip. Steelix's rock-like sections don't look perfect and can easily be mistaken for rocks, for they have many chips and scrapes all along them from fights and tunneling.
Steelix can be obtained by making an Onix hold a Metal Coat and trading it. Steelix obtains a mega evolution in Omega Ruby and Alpha Sapphire.
Brock's Steelix is one of Brock's Pokémon and his father, Flint caught as an Onix in Kanto. It evolved into Steelix (not shown) and was discovered in Battle Frontier series. Steelix was given to Brock's younger brother, Forrest. Olivine City Gym leader Jasmine also owned a Steelix. In the Diamond and Pearl series, it was followed by Canalave City Gym leader and Roark's father, Byron also owns a Steelix as it shares its powerful Screech ability with Roark's Onix.