Terry Pratchett and Neil Gaiman.
GAIMAN: "We’re working on seeing how many smart-alec answers we can come up with when people ask us how we collaborated."
PRATCHETT: “I wrote all the words, and Neil assembled them into certain meaningful patterns… What it wasn’t was a case of one guy getting 2/3 of the money and the other guy doing 3/4 of the work.”
GAIMAN: “It wasn’t, somebody writes a three-page synopsis, and then somebody else writes a whole novel and gets their name small on the bottom.”
PRATCHETT: “That isn’t how we did it, mainly because our egos were fighting one another the whole time, and we were trying to grab the best bits from one another.”
GAIMAN: “We both have egos the size of planetary cores.”