Michael "Mike" Rianda (born December 25, 1984) is an American cartoonist, director, writer, and voice actor. He is known for his work on Gravity Falls as a creative director and writer for season 1, and creative consultant for season 2. He is also known for directing, co-writing, and co-starring his feature directorial debut The Mitchells vs. the Machines. Rianda was born on December 25, 1984 in Salinas, California. He attended the California Institute of the Arts after he "drew and said amusing things" in school, studying character animation. Rianda also started writing and directing two short films at the animation school titled Everybody Dies in 90 Seconds (2008) and Work (2010). He became a creative director and writer on the Emmy-award winning Disney Channel animated television series series Gravity Falls, until his departure in 2013. Mike also voiced Lee, Thompson, Mr. Poolcheck, and the additional voices. Rianda later returned and served as an creative consultant for its second season. In 2021, he directed and co-written, along with Jeff Rowe, The Mitchells vs. the Machines, in which he also voiced Aaron Mitchell. The film was released on Netflix on April 30, 2021.