When the two superstars of slasherdom finally got to battle it out in Freddy Vs. Jason the writers came up with a pretty convoluted reason for their conflict- Jason refused to let Freddy boss him around.
But if we've learned anything about these characters it's that they both have a penchant for killing people that defines their very existence, so rather than enemies Freddy and Jason would have been soulmates.
And, as this comic by JHALL and Tristan Cooper shows, the two would have preferred to snuggle on the couch and watch the live-action Scooby Doo movies rather than fighting. That is, unless Freddy said something mean about Jason's mom...
-Via Dorkly