Most Information and Bio picture are from Xbox360Achievements.org and its posters xRogue 5x and Fizzmatix. Original thread can be found at this location.
Grundel is a Most Wanted Ghost in the online mode of Ghostbusters: The Video Game, not to be confused with the ghost from The Real Ghostbusters and Extreme Ghostbusters of the same name. He is a variation of Crusto and can be fought after completing five Protection jobs in any Museum level. He only appears in the Museum levels.