David Howard Thornton (born 20 November 1979) is an American actor. He is an actor known for work in stage, film, and voice over. He is best known for his roles as Grandpa Who in the 1st- 5th national tours of Dr. Seuss' How the Grinch Stole Christmas: The Musical, the voice of Shizoku and others in the video game Invizimals: The Lost Kingdom, The Joker in the YouTube series Nightwing Escalation, and Art the Clown in the film Terrifier.

• Terrifier (2016)

  
• Terrifier 2 (2022)

  
• The Mean One (2022)

  
• The Mean One (2022)

  
• Terrifier 3 (2024)