The “Over Four Hundred” Club is a group of ghosts from the Haunted Mansion.
Presumably gathering, as its name implies, several ghosts bonding over their great age, the Over Four Hundred Club can often found gathering at the banquet table in the Haunted Mansion's Great Hall. Among its members are Great Caesar's Ghost, the Crowned Ghost and Roderick Kilroy, as well as several other spooks whose names and origins are considerably more unclear. The Club is usually seen taking part in the birthday celebrations of the Birthday Girl, who does not appear to be a member.
Behind the scenes
The group of ghosts at the table in the Mansion's Ballroom, designed by Marc Davis, first appeared in August of 1969 when Disneyland's Haunted Mansion opened to the public. The idea that they constitute the "Over Four Hundred Club" originates in the later TV special Spooks and Magic.