Long, long ago, the Crocodile Beast was a pet of the Fire Tribe with others until the war and Chi water caused many of his crocodile brothers to evolve. Because he knew that they all had inner chi, the Crocodile Beast chose not to drink the Chi water and instead left Chima with seven other Legend Beasts, vanishing into the Outlands, but said to return when Chima needed them most.
He was acquainted with Lavertus and enjoyed his cupcakes. When the Dark Tribes were created, the other Legend Beasts were captured so the waterfalls of Mount Cavora would not restart while they stole all the Chi, but the Crocodile Beast escaped with Queen Crunket thanks to Shadow Wind.
The Beast got caught in a trap on the edge of the Outlands by the Spider Tribe, but Shadow Wind directed Laval there for him to find it and help it escape the trap and into Chima. Laval and Crunket then rode it to stop the battle at the Lion Chi Temple, where Crunket revealed what had happened to them.
He was given armour by the Tribes of Chima and had Cragger's Royal Vengious mounted on his head before they went into the Outlands with Cragger riding him. After escaping the deadly chompy plants and the Bat Tribe, they found themselves in Lavertus' Speedorz gauntlet and made it into his Outland Base, where Lavertus welcomed them in.
He was ridden by Cragger to the Scorpion Cave to rescue the Raven Legend Beast. They kept the Scorpions busy while Laval, Lavertus and Razar rescued the Raven Beast. After the Raven Beast helped defeat the Scorpions, they fled back to the Outland Base.
Cragger later rode him again to rescue the Eagle and Bear Legend Beasts, and thanks to Rhogon's Rhino Beast making him smart, he was able to get them a shortcut to the see-saw trap and release the water to break Laval, Bladvic and the Bear Beast's fall. Cragger and the Crocodile Beast then rescued him. Gorzan and the Gorilla Beast hopped on the Croc Beast to get to shore, then Cragger and the Bast went back to the lair.
Worriz later pit they Legend Beasts against each other to see which was the mightiest, and the Croc Beast stopped the Raven Beast from dropping the rock into the basket when they got distracted by Lavertus' cupcakes.
The Crocodile Beast was ridden by Laval back to the Scorpion Cave when Cragger was captured with Worriz. After rescuing Cragger, Worriz, King Crominus and the Wolf Beast, Cragger mounted the Crocodile Beast again.
Cragger and Crominus rode the Crocodile Beast throughout the final battle in the Scorpion Cave until it collapsed because of Rogon and Scorm. Thanks to Lavertus and Rinona in the Wind Shadow, they were able to escape before it collapsed. The Lion Beast and the Crocodile Beast were the last out just before the cave came down.
The Legend Beasts then all returned to Chima and restarted the Chi falls, entering Mount Cavora.
Laval, Cragger and Eris later found the Phoenix Fire Temple in Mount Cavora and the Legend Beasts, who had somehow had their armour removed, used their fire power to send them up into the temple to meet the Phoenix Tribe.
The Legend Beasts later attacked Laval and Cragger with their fire power as part of the trial to see if they were worthy of the Fire Chi, which they passed.