http://www.snopes.com/holidays/christmas/humor/mondegreens.asp

http://www.snopes.com/holidays/christmas/humor/mondegreens.asp

here are some misheard lyrics from a urben legend site 

yumikos personal faves:

Angels we have heard on high 
Sweetly singing o’er the plains, 
And the mountains in reply 
Echoing their joyous strains. 

Born in a Chelsea stable 
Born in a Chelsea stable
 

Gaily they ring 
white people sing 
songs of good cheer, 
Christmas is here.

 

Don we now our day of peril, 

Fa la la, la la la, la la la. 
Troll the ancient Yule tide carol, 
Fa la la la la, la la la la. 

Noel, Noel, Noel, Noel, 
Barney’s the King of Israel. 

Outside the snow is falling, 
And friends are calling, ”You fool!” 
Come on, it’s lovely weather 
For a sleigh ride together with you.