After being hugged by an "Alpha Hug Wolf," Finn transforms into a "Hug Wolf" himself every night. Instead of violence, he feels an uncontrollable, "love-crazed" urge to hug others until they are literally suffocated or "infected" by the hug.
Adventure Time (TV Series 2010–2018) - Episode list - IMDb "Adventure Time" Hug Wolf(2012)
The episode was storyboarded and written by Somvilay Xayaphone and Bert Youn . After being hugged by an "Alpha Hug Wolf,"