Funny campaigns

Everyone loves a funny campaign, so I figured I should create a forum for it, and have you guys share your experiences.  

Not from a campaign I am in, but from a fellow DM and one of the more amusing D&D anecdotes I have heard recently:  My friend was DMing a campaign and their party came across a lesser demon lord.  The party asked the demon his name, and the DM, on the spot, responded "I don't know.  Hell-man?"  One of the members of the party responded "Let me get this straight, this is Duke Hell-man?  Soooo, literally Duke's and Hellmann's?"  And that is the story of how my friend's D&D campaign went from being a fairly standard fantasy homebrew to being completely derailed as the party and their new demon friend started and now run a demonic mayonnaise company. 

Huh.  Satanic mayo.  Who would have though.

There's a thread for Funny Quotes from Your Campaign out there already, which covers this sort of thing - might be worth a read through if you're after those sort of stories!

For campaigns which are inherently funny, I have a oneshot I ran a little while ago which centers around a Cheese Chasing festival. The players were laughing for the majority of it, so I call that a success!