Michael John Kricfalusi (/ˌkrɪsfəˈluːsi/; born September 9, 1955), known professionally as John K., is a Canadian blogger, former animator and voice actor. He is best known for creating the Nickelodeon animated television series The Ren & Stimpy Show, voicing Ren and being the original singer for the song Happy Happy Joy Joy on the show and for voicing Dr. Theopolis in Buck Rogers in the 25th Century and in the 1979 film of the same name. He was born in Chicoutimi, Quebec.
In 2018, Kricfalusi was accused of sexually abusing underage girls in the late 1990s. Kricfalusi released an apology for his behavior, blaming his bipolar disorder.