The Ribular Island Battle Royale is a sidequest for Fossil Fighters: Champions. It is part of Joe Wildwest's Super Caliosteo Cup Tournament. It takes place on Ribular Island and is open to carnivorous Vivosaurs only. Once the Ribular Royale is finished, the player can move on to the Battle Royale on Cranial Isle. The player is rewarded with the "Mini-Rupert" and "Cool Rupert" icons as well as a Legs Mask upon winning the tournament.
Round 1- Minister Pomposa. Your first match in the Ribular Island Battle Royale pits you against a familiar face - Minister Pomposa. He states that he has decided to take up Fossil Battling and that he wishes to try his skills in the Caliosteo Super Cup.
Round 2- Rosie. Your second match in the Ribular Island Battle Royale pits you against Rosie herself. She, after introducing herself, gives a lengthy speech entailing the Hero's apparently inevitable defeat.
Round 3- Rupert. Your third and final match in the Ribular Island Battle Royale pits you against your good friend Rupert. He swears to the Hero that he will defeat them, saying that he has suffered defeat in their hands too many a time.