The Cramp Twins

The Cramp Twins is a British-American-Canadian animated series created by cartoonist Brian Wood for Cartoon Network. It is about Wayne Cramp and Lucien Cramp, non-identical twin brothers who live with their germophobic mother and their Western-obsessed father  in the fictional town of Soap City. Wayne and Lucien's personalities clash, and they rarely get along. Wayne has a friend called Dirty Joe, who owns a dump, and neighbor Wendy Winkle has a crush on him, but he hates her. Lucien's friends include environment-friendly Tony Parsons and Mari

Hankenstein / Cricket Slayer ( Episode 6, Season 3 )
Lucien feels guilty for the death of a rare species of cricket., his friend Mari resorts to hypnosis, in order to make him forget about the guilt. She does help him but not before making him act like a duck, Lucien starts feeling better but a nightmare convinces him that he's not fully healed, so he resorts to hypnosis once again. The second time, due to killing an insect while performing her hypnosis session, Mari accidentally hypnotizes Lucien into having a desire to crush everything. Later Wendy seeks Mari's to deal with her love problem but Mari just hypnotize her to act like a duck.