Claymation Comedy of Horrors, on CBS
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This first aired in May 1991, but as far as I can recall, the first time I ever saw it was when I watched it on DVD on Halloween, 2016. The special was made by Will Vinton, and the main reason I got the DVD was for his Claymation Christmas Celebration. (Aside from those two specials, the DVD also includes an Easter special.) So, I guess this Halloween thing came the year before the Easter special, but I ended up seeing the Easter one first. Both the Easter and Halloween specials feature a greedy, obnoxious character named Wilshire Pig. But I'd say even though he was introduced in this special, it really doesn't matter which one you see first.

Anyway, it starts out "many years ago," with Victor Frankenswine creating a monster. However, his castle is stormed by peasants before he can bring it to life. In the present, Wilshire Pig and Sheldon Snail are working on an amusement park ride on Halloween, which is just designed to shake people down for loose change. Of course it explodes, and leaves a crater in which Sheldon discovers the diary of Frankenswine, which imprints a map on his tongue, which Wilshire wants to follow to find the castle and claim the monster as a prize. (Though to get Sheldon to go along with it, Wilshire claims he just wants to get a free tote bag, one of several random prizes that were mentioned along with the monster itself.) When they get to the castle, they find a bunch of monsters having a Halloween convention, and they must prevent the monsters from discovering that they're mortal. So Wilshire claims to be Dr. Jekyll and says Sheldon is Mr. Hyde. (Already I don't get how that's supposed to work, but whatevs.) Sheldon just wants to leave, but Wilshire forces him to stay so they can search the castle for the laboratory, to claim the monster as his own and use it to rule the world, or whatever.

I don't really want to say any more about the plot, but I guess it was reasonably amusing. I'm not quite sure whether I found it more or less entertaining than I did the Easter special, so I'm just giving it the same rating. And anyway, I'm sure my appreciation of this one wouldn't differ more than a quarter of a smiley, one way or the other.