Grolem 13 (also known as Bigum Aerum Tornadus Recyclus) is a villain and boss character from Rayman 2: Revolution. He is also the Guardian of the fourth Mask of Polokus.
When Rayman comes too close to the fourth Mask, hidden in floating blue crystal in the Iron Mountains high in the clouds, Grolem 13 appears there and shoots a tornado at Rayman. He has more attacks than the other Guardians: he can throw icicles (like Axel) and ice boulders, creates thunderstorms and lightnings or tries to smash him with his fist.
He also shoots small storm clouds at Rayman which Rayman can move above Grolem 13's head with his fist. When there are enough clouds, they grow darker and a bolt of lightning strikes out of them, hitting Grolem 13's head.
After doing it for three times, Grolem 13 gets flattered and falls down. The ice around the fourth Mask breaks off, allowing Rayman to take it.
- In the Japanese version of Rayman 2 Revolution, Grolem 13 looks just like Axel for unknown reasons.