Bruno sent Onix to test Red, who dodged Onix's attack. Red's Gyara fired Hydro Pump on Onix, who evaded the attack and used Wrap on Gyara. Gyara bit Onix, who used Dig to go underground. To stop Onix, Red sent Saur, whose vines bound Onix when it came out. To counter that, Onix used its tail to attack Saur and Red from behind, causing them to fall into a hole Onix dug through. As Onix went to attack Red and Saur, Bruno stopped it, for a bunch of Diglett were passing by. Bruno explained he couldn't let Onix attack, as the tunnels were home to Diglett and Dugtrio. Just as Onix and Bruno went to attack, they were stopped as Bruno felt certain pain.
To stop Yellow and Blaine from interrupting his battle with Lt. Surge and Bill, Bruno sent Onix. Onix crashed through the icy wall and bound Yellow and Blaine with its tail. The damage caused by Onix caused Yellow and Blaine to be sweeped away by a torrent.
- At the back cover of Volume 5, Bruno is shown with two Onix.