Marvin John Nance (December 21, 1943 – December 30, 1996), known professionally as Jack Nance and occasionally credited as John Nance, was an American actor.He was known for his work with director David Lynch, particularly for his roles in Eraserhead, Blue Velvet, Wild at Heart, and Twin Peaks.I Don't Know Jack, a documentary about Nance, was funded by David Lynch and released in 2002.