Mangler (voiced by Joey Lotsko) is the leader of the flying squirrels and becomes a loyal follower of the Forbidden Arts out of fear for his life, thus making him one of the main antagonists. He is the oldest member of the flying squirrels, but is ruthless, relentless, and bitter - and refuses to accept failure in the Scullions' search for the Swan Princess, fearing whatever punishment the Forbidden Arts has in store for him should they fail. In an attempt to kill Odette, he inadvertently shoots Jojo as he leaps in the way to protect her, but the young squirrel is quickly revived as the intended target gives him an antidote for the poisonous dart. The other Scullions show outrage towards his actions, but he makes another attempt at Odette's life using one of the many boobytraps set around the flying squirrels' campsite. However, the true prophecy is revealed (apparently as a result of Odette saving Jojo's life) and the flying squirrels turn against Mangler, realizing that he had been lying to them and had led them on a wild goose chase, they banish him from the Scullions and he is exiled from their territory - just as he had done to Scully years before.
Even after his banishment, he still shows great persistance in killing Odette - perhaps still fearing the Forbidden Arts' wrath. He even goes so far as to follow her and Scully on their way to save Alise, hoping to succeed in his final assassination attempt. He and Scully partake in combat after the latter tries to defend Odette from an ambush, during which the two fall off a ledge and into a chasm - Scully is shown to have made it out of the chasm (though it is never revealed how), but Mangler is never seen again, thus insinuating that he most likely perished from the fall.