Josh Weinstein (later known as J. Elvis Weinstein) is one of MST3K's original writers and cast members. He portrayed Dr. Laurence Erhardt, colleague to Dr. Clayton Forrester, and was the original voice and puppeteer of Tom Servo and Gypsy. He also voiced Crow T. Robot in the first broadcast episode and a few other episodes on KTMA.
He departed from the show at the end of its first national season. The reasons given for his departure have varied. According to Satellite News, when asked in an interview in the summer of 1990 why Josh was leaving, Jim Mallon stated "creative differences", as the show began being scripted instead of being ad-libbed. Joel Hodgson offered his own take: "Let me put it this way," he said with some weariness in his voice, "he's 18 years old." Weinstein's youth and relative inexperience was said to have annoyed his older co-workers. In an interview, he stated the show simply quit being fun for him when they moved from KTMA to The Comedy Channel because it became "a business".
In more recent interviews, Weinstein has gone into greater detail about his departure from the show. On Bill Corbett's Funhouse, Weinstein explained that when the show was sold to cable TV, Hodgson and Mallon refused to make him an equal partner in the company (unlike Beaulieu and Murphy) and paid him significantly less than the other cast and writers. Weinstein speculated that his youth and aggressive attitude may have contributed to the treatment he received. He stated that he has since resolved his issues with Hodgson and the other cast and writers, but he has little interaction with Mallon.
- "I met Joel after he came back to Minneapolis. I was 15 and had just started doing stand-up. He had an air of specialness about him, because he had been in the big time. He was definitely an artist among comics."
- "We eventually realized, hey, this might be funnier if we had some jokes in our back pocket."
- (on choosing the moniker "J. Elvis") "I decided on it because when I joined the writer's guild there already was a Josh Weinstein, and I gave myself the Elvis because I loved that it gave me the initials J. E. W. and also somewhat inspired by being a fan of Elvis Costello, but mostly it's about J. E. W."
- (on the difference between geeks and nerds) "Geeks will talk to us, nerds find us too weird." 
Non-MST3K riffing projects
In 2007, he joined Hodgson, Beaulieu, Mary Jo Pehl and Frank Conniff in Cinematic Titanic, a riffing project created by Joel that produced seven studio episodes, five live DVDs and toured extensively through 2013.
His final riffing project to date is a commentary track on the Blu-ray for The Heat, a film by Paul Feig. He was joined once again by Hodgson and Beaulieu to riff the film.
From 1999 to 2000, Weinstein was a writer and executive producer on the cult-favorite NBC series Freaks and Geeks, which was created by Paul Feig and executive produced by Judd Apatow. The show also featured Trace Beaulieu and Joel Hodgson in supporting roles.
Weinstein later became the Head Writer for the TV series America's Funniest Home Videos for many years.
In fall of 2014, Weinstein appeared in the music video comedy short The Frank along with other MST3K members. It was made available exclusively for DVD.
In 2017, Weinstein began co-hosting the podcast Thought Spiral along with comedian Andy Kindler.
Weinstein also became a documentary filmmaker. His first feature I Need You to Kill (about stand-up comedy) was released in late-2017. Additionally, since 2013 he has been working on a documentary about music which is planned for release in 2019. He also stars in the 2019 independent film The Fiddling Horse.
In 2019, Weinstein produced his first stand-up comedy album, entitled Chunks.
- Weinstein's last name is pronounced to rhyme with Einstein.
- Josh Weinstein at the Internet Movie Database
- Stinkburger Inc
- WIRED Magazine Mystery Science Theater 3000: The Definitive Oral History of a TV Masterpiece
- MutantReviewers Wordpress site on MST3K's nerdy nature