• English / United States: Forest's Rhyperior
• Japanese / Japan: ジローのドサイドン
• Japanese (Romanized) / Japan: Jirō no Dosidon
• Japanese (TL) / Japan: Jiro's Dosidon

Forest's Rhyperior was revealed when Forrest sent it out to battle against Nurse Joy to see if Forrest was good enough to be the Gym Leader of the Pewter City Gym. Forest's Rhyperior was up against Nurse Joy's Latias in the battle but its strength and determination showed that is was trained well by Forrest. It's Dig/Megahorn combination proved to be very effective against Nurse Joy's Latias but it still wasn't enough to defeat it. Even though Forest's Rhyperior lost the battle, Nurse Joy recognized that it was a close battle and she was satisfied with Forrest's ability as a Gym Leader as Forest's Rhyperior really showcased that to her in the battle.