Mars Callahan (born 1971) is an American actor, film director, producer and writer.He is perhaps best known for the film Poolhall Junkies where he served as director, actor and screenwriter.At the age of eleven, Callahan toured with a children's musical group through thirty-seven states. At fifteen he received his first acting role in the television series The Wonder Years. After honing his acting skills in television he tried for the big screen and soon appeared in various films.