This episode is a bit of a legend. That one time a Saturday morning cartoon actually had a Lovecraftian horror, and the most well-known one too.
For those unawares The Real Ghostbusters is the Saturday morning cartoon series based on the successful movie Ghostbusters called the Real Ghostbusters because of an old show called Ghostbusters that also released an animated series to try and piggyback on the success of the name from the movie.
In the Episode while it treats Lovecraft as a person who wrote fictional stories it says those stories were based on actual things… so… yeah its having its cake and eating it.
The story opens up as a copy of the Necronomicon a series of stories used as a basis in Lovecraftian books (yes it appeared before Evil Dead) is stolen just as it was going to go on display, the security guard passing out after his arm being grabbed by a tentacle monstrosity.
The episode basically plays out like a fanservice of Lovecraft monsters and elements with the book itself having come from Arkham, there’s a cult of Cathulhu (and yes that’s how its spelled in the title so that’s what I’m using here) and Lovecraftian monsters in the form of Star Spawn of Cathulhu a shagoth and of course the big guy himself.
They also openly describe Cathulhu as being far more powerful than Gozer from the first movie so it really does appear that the writer was really wanting to big up the Lovecraft monsters, and given this is the one time I can recall they appear in a children’s cartoon I can understand that.
The whole thing does play off very silly and rather underwhelming. But this is also before the series got ruined by the money people making all the more kidified so it still retains that dark element that makes the cartoon so fondly remembered (yes Slimer does not appear in this episode)
The climax of the episode is with the confrontation with Cathulhu as the Ghostbusters aided Alice Derleth (no idea if she’s a reference) must stop the great old one and banish him back till the stars once more align. (I think he was a bonus reward for backers in a Ghostbusters board game too).
The main gimmick and the whole reason you would watch this episode is the fact it’s an episode of a children’s cartoon with a bunch of Lovecraft monsters. Heck we rarely get that today with there being a few stand outs so the fact we got one nearly 40 years ago is worth checking out.