In "Wrath of the Librarian," when Courage held the book with his glove, it had four fingers. But Courage, himself, only has three fingers.
In "Cabaret Courage," they're in Hollowood, but in "Mega Muriel the Magnificent," on the mountain that turned inside-out, it said, "Hollyweird."
(Eustace is singing, "Swanee River")
Muriel: Eustace really never could sing.
Blob: If I like your performance, I'll give you a solid, gold truck.
Eustace: Happy birthday to me!
Eustace & The Pickle Pirate: Spines and spikes!
In "Wrath of the Librarian," the fine was $3,972.43. So the library must have charged Courage about $5.00 per day it was late.
The last appearance of Dr. Vindaloo.
Di Lung's name was first seen in "Cabaret Courage" on his autographs.
In "Cabaret Courage," Muriel said that they were in "Hollowood." Back in 1996, Rocko's Modern Life had a parody of Hollywood, too, with the same name -- "Hollowood."
In "Wrath of the Librarian," the sign above the cinema says, "Bride of the Swamp Monster" for a scene.
"I'm called Little Buttercup..."
The song Muriel and Di Lung both try to sing is "I'm Called Little Buttercup" from Gilbert and Sullivan's famous 19th century comic opera, "HMS Pinafore."