Scooby-Doo in Supernatural!
The episode is due to arrive on North American television around March 2018 and the actors have recorded their speeches.
According to producer Andrew Dabb, the episode will be more obscure than the already produced Scooby-Doo drawings:
"It will be a Supernatural episode with Scooby-Doo, not a Scooby-Doo episode with the boys. It's more adult than the average Scooby-Doo episode"