James Gunn would love to see a 'Scooby-Doo' and 'The Suicide Squad' crossover movie.

The director of the latter flick - which is due out in 2021 - took to Twitter to answer his followers' questions and whilst he said it would be impossible to do a 'Guardians of the Galaxy' and 'Scooby-Do' movie, due to legal issues regarding licensing, he suggested his upcoming superhero film based on the DC Comics antihero team Suicide Squad - the standalone sequel to 2016's 'Suicide Squad' - could come together with the crime-solving Mystery Inc. gang for a new motion picture.

In 2018, the crossover movie 'Scooby-Doo' and 'Batman: The Brave and Bold' was released by Warner Bros., which saw Scooby and his pals team up with Batman and other DC Comics superheroes to defeat a new villain.

When a fan suggested the 'Guardians' and 'Scooby-Doo' (Marvel) crossover, Gunn replied: ''Scooby & the Guardians might be unlikely considering it's Warners/Disney. But, you know, an animated Mystery Ink/The Suicide Squad film is always possible. (sic)''

Gunn also penned the script for 2002's live-action 'Scooby-Doo' movie and 2004's follow-up 'Scooby-Doo 2: Monsters Unleashed'.

And he previously revealed this year's CGI movie 'SCOOB!', the first time Scooby has hit the big screen since 'Monsters Unleashed', was originally set to be PG-13, but it was changed to PG after causing outrage among some parents.

He explained: ''The movie was originally meant to be PG-13 and was cut down to PG after like three parents were outraged at a test screening in Sacramento. The studio decided to go a more family friendly route.

''Language and jokes and sexual situations were removed, including a kiss between Daphne and Velma. Cleavage was CGI'd over. But, thankfully, the farting remained.''

The 53-year-old filmmaker admitted he was disappointed by the rating change.

He added: ''I thought at the time the rating change was a mistake.

''I felt like a lot of teens came out for the first film and didn't get what they wanted (and didn't come back for the sequel). But today I don't know. So many young kids loved those movies, which is pretty cool.''

'SCOOB!' sees Frank Welker voice the titular Great Dane mascot of Mystery Inc.

Will Forte stars as Shaggy Rogers, Gina Rodriguez is Velma Dinkley, Zac Efron voices Fred Jones and Amanda Seyfried is Daphne Blake.