Quaggle is a highly sociopathic troll who often speaks in rhyming riddles. Until the episode "Trolling for Terror", he had not the slightest clue what money was, sleeping on a pile of uncashed paychecks and using them to build various furniture for his home under a bridge.
Leonard Powers tries to teach Quaggle how to blend in into society, which consisted of rather controversial lessons like how to avoid paying debts, running away from the police or betting on horse races. He also gives him some misanthropic and anarchistic philosophical insights.
He has tried working at a toll bridge, which ended with a disaster since he wouldn't let anyone through who wouldn't solve his riddle. However, after he aided Clark Dungaree in a plot to thrill Mark Lilly in Clark's newest reality television show "I'm gonna f**k with you, Mark Lilly", he got his own quiz show, "Riddle Me This!".