At Comic Riffs, Michael Cavna has something special for Richard Thompson fans: Some concept art he did for the movie "Inside Out."

Thompson, who died last month of complications from Parkinson's disease, did the sketches at the request of filmmaker Pete Docter back in 2010. Docter was just starting to flesh out the characters, and he asked the "Cul de Sac" creator to help. Thompson drew some sketches in comics format, one of which included an early version of the character "Sadness." “We developed past that [for the film], obviously, but [Thompson’s] sense of character, of being able to tap into that — real observations from his life and who knows where else,” Docter said.

RELATED: ‘Cul de Sac’ creator Richard Thompson passes away

The drawings are a posthumous treat for Thompson fans; they are not just static drawings of characters but rough comic strips that display sharp humor and tell a story that expands beyond the limited space of the borders.

Two of the sketches are up at Comic Riffs.