Apparently, Robin Williams wasn’t afraid to make an ass of himself if it meant pulling off a good prank.

Thomas Tulak, who played one of the Lost Boys in the 1991 film “Hook,” said Thursday that “Hook” star Williams mooned the cast on set to thwart director Steven Spielberg’s effort to establish order.

Tulak, who played Too Small in the film, relayed the tale during a Reddit Q&A.

Also Read: The Boy Who Inspired 'Hook' and 19 Other Little-Known Facts as Film Turns 25 (Photos)

Asked about his favorite memory of Williams, Tulak recalled, “I had the best time hanging out with Robin off set, more than anything that was actually on set.”

Then Tulak offered, “that, or the time he jumped on the top of the pirate ship and mooned the entire cast and crew, while Steven Spielberg was trying to gain control of the crowd… chaos ensued :P”

Tulak went on to recall how Williams, who took his own life in 2014 at age 63, “was dedicated to making every one around him happy. and he did so in spectacular fashion. he gave and gave of himself.”

Also Read: Robin Williams' Widow on His Struggle With Neural Disease: 'He Had Chemical Warfare in His Brain'

Asked what he would do if he was able to travel back in time, Tulak said, “[Probably] try to stay in touch with Robin over the years… I dunno if I coulda helped ease his depression, and save his life, but I would have wanted to try.”

Remembering Robin Williams: A Life and Career in Pictures (Photos)

Williams made his big screen debut in little-seen 1977 comedy "Can I Do It 'Till I Need Glasses?"
Williams made several appearances doing sketches on 1977's "The Richard Pryor Show"
Quirky comedy series "Mork and Mindy" premiered in 1978 and put Williams on the map.
Christopher Reeve presented Williams with a People's Choice Award for Favorite Male Performer for "Mork and Mindy" in 1979.
"The World According to Garp," 1982
Williams was received his first Oscar nomination for his role in 1987's "Good Morning, Vietnam."
O Captain! My captain! Williams captivated a young audience by playing an unorthodox professor in 1989's "Dead Poets Society."
"There you are, Peter." Williams played a grown up Peter Pan returning to Neverland in 1991's "Hook."
Williams memorably voiced the Genie in Disney's animated classic "Aladdin," which came out in 1992.
"Mrs Doubtfire" was released in 1993 and remains one of Williams' most iconic roles
Williams played a wild man returning to civilization as a result of a board game gone very wrong in 1995's "Jumanji."
Williams played one half of a flamboyant gay couple opposite Nathan Lane in 1996's "The Birdcage."
Williams won the Best Actor Oscar for 1997's "Good Will Hunting" with Matt Damon and Ben Affleck
Williams celebrating his Oscar win for "Good Will Hunting" in 1998 with Matt Damon and Ben Affleck, who also won Oscars for Best Screenplay
For a film in which he plays a clown, 1998's "Patch Adams" was a somber and dramatic turn for Williams.
Williams went dark and twisted for Mark Romanek's 2002 cult favorite thriller "One Hour Photo."
Williams played Teddy Roosevelt in 2006's "Night at the Museum" and reprised the role in the 2009 sequel. The threequel, "Secret of the Tomb," is set for release in December.
Williams with his daughter Zelda in 2009.
Williams with his wife, Susan Schneider, in 2012. The couple was married in 2011.
Williams played father to Sarah Michelle Gellar in his return to TV, 2013 CBS sitcom "The Crazy Ones."
Williams played President Dwight D. Eisenhower in Lee Daniels' "The Butler" in 2013.
The last Williams film to be released while he was alive was 2014's "The Angriest Man in Brooklyn," which co-starred Mila Kunis.
"Night at the Museum: Secret of the Tomb" was the last studio film Williams had completed prior to his death. He posted this photo with his stand-in and stunt double in May.
The last photo Williams ever posted to social media was this #tbt featuring him with his daughter on July 31: "Happy Birthday to Ms. Zelda Rae Williams! Quarter of a century old today but always my baby girl. Happy Birthday @zeldawilliams Love you!"