I don't care, what lawsuits say. My Tiefling warlock has her powers from Cthulhu in my headcanon.
Tbh I know D&d groups that play Cthulhu crossover with homebrew rules.
I guess the problem here is, that you aren't really supposed to kill a GOO or an Elder God, so it might end very deadly for your characters. And as a rule (at least in our groups) you put much more time and effort into making a D&D- character than one for Call of Cthulhu, because you just know, that the latter one will eventually go mad and/or die.
