An annual event. Each year I GM a stand-alone scenario that runs two to four evenings, starting on the Friday closest to Halloween. Sometimes it borrows characters from a current campaign, sometimes it is peripherally attached to current campaign continuity, but usually is a self-contained idea, with characters generated by me specifically for the scenario.
Monsters and goblins from movies, books, songs and comics crash a party given by the Artificer of Sirav. The players keep alive by name dropping to keep monsters busy with each other. Saved by the arrival of the Great Pumpkin, who gives the characters (their greed was soooo sincere) 'gifts'.
Experimental dungeon with visuals (illustrated puzzle/rooms) and a soundtrack that guided characters through the Hotel Napa Valley. Met the demon lord of Rakshasas and the Evil God Set. With help from divine allies (the Phantom Stranger and the Specter) were able to force Set back to his home dimension.
A super hero dungeon: James Bond, Princess Leia, Prince Corum, Robin Hood, Ultra Boy, Starbuck, and Princess Goodness, collect the twelve greatest talismans of power. Why? Saron wants them so he can open a pan-universal gate in preparation for invading every D & D universe existing in one grand bid for multi-universal domination. How can they refuse, they were tricked into wearing the nine rings!
The characters are dolphins, fish and mer-people. They try to find and hide the crown of the ancient evil despot buried in the ancient sunken city. They must find it before the evil sorcerer Black Adam can wrest it from its watery storehouse.
Occultists, charlatans, military men, and Sherlock Holmes answer INTERPOL's call to investigate world wide thefts of flu vaccine. Can they stop Ras Thavas, the Gheks and the Morlocks?
American agents posing as roadies for Greg Jervain's European Comeback Tour meet a Polish Count. Using healing magic this vivisectionist is studying how the human body works. After all, the Count can cut a person open and keep them alive indefinitely, allowing him to study the workings of the internal organs. Of course he has to remove their vocal cords to keep them from screaming. Will our agents further the cause of medical science?
Paleolithic pre-verbal band guided by the magic magpie try to find a new home during a time of famine.
The crew of the Osprey visit a ghost ship and are forced to take refuge from a storm in the negative material plane. There they meet a mad healer / vivisectionist.
Trouble brews between Heaven and Paradise when Willy Tonka starts a candy factory where the River of Milk and the River of Honey meet. The crew of the Osprey halts the formation of a new outer plane.
The crew of the Osprey finds the long lost sunken city of Alpha Complex.