The Onix line is available in all Kanto, Johto, and Sinnoh-based games, as well as the Unova sequels. It evolves by trading it with an attached Metal Coat. In some games, Steelix can also be found in the wild. Onix can also be found in ORAS with the DexNav and in Ultra Sun and Ultra Moon through Tuesday's Island Scan.

Completed analyses of the Onix line so far: