Roark's Onix (anime)

Roark's Onix was Roark's second most used Pokemon.

Biography
Roark's Onix was first used to battle Paul's Elekid and Chimchar in Shapes of Things to Come. It gained the advantage over Elekid due to its large size and immunity to Elekid's electric attacks. Elekid managed to paralyze Onix with Static but the Rock Snake Pokemon used Stealth Rock and finally Paul recalled Elekid and replaced it with Chimchar. The Fire Monkey Pokemon avoided Onix's attacks by using Dig and defeated the massive Pokemon.

Onix appeared again when Roark battled Ash, easily defeated his Turtwig with a single Double-Edge. It then battled Pikachu and one by unleashing a Screech technique that was so powerful that it blew Pikachu back into a rock defeating it.

Onix battled Pikachu a second time during Ash and Roark's rematch. During the battle Pikachu used a Thunderbolt that was powerful enough to actually hurt Onix, despite it being a Ground type. Stunner by Pikachu's incredible electrical power, Roark's reacted to slowly to form an effective counterstrike and Pikachu lunged forwards and smashed Onix with Iron Tail knocking it out.