Sir Gawain and the Green Knight has got to be one of the funniest pieces of Arthurian lit, for all that it's written in serious and heroic tones. I mean, you have:

--a green knight and horse
--the same knight can pick up his head and reattach it after being beheaded
--Sir Gawain, who's stupid enough to take his bet
--a lord's wife who tried to get it on with Gawain several days in a row (lately I'm thinking he refused because then what would have he given the lord when asked what he got that day?!)
--the lady turns out to be Morgan le Fey
--just in case anybody's missed it the first time, the knight and his horse are green!!!

I do think the author(s?) must have been drunk at the time of the writing, and/or in an extremely humorous mood.