... (makers of the Call of Cthulhu roleplaying game) own the copyright on Lovecrafts' work, including the concept of Cthulhu - so anyone who wants to avoid legal problems spells it differently. Chaosium's lawyers will be first to get it from the big guy when the stars are right...
Incorrect answer. Arkham Press make vague claims as to the copyright on Lovecrafts work but at a push they will admit that his stuff is entirely public domain, they just have the rights to publish it. That is why the Lovecraft Library sites on the net are 100% legal.
Bitter, twisted and better than you.