The Incredible Hulk #376 The Incredible Hulk vs. The Incredible Hulk.  By Marvel Comics. Titled “Personality Conflict.” Written by Peter David.  Cover by Steve Geiger and Bob McLeod.
Bruce finds himself unable to sleep because his two personas continue battling it out in his mind.  The struggle takes a turn for the worse when Bruce’s hands transform into the gray Hulk.   Bruce explains to his allies that the gray and green Hulks are battling in his mind.

He opens a door between both Hulks and an intense battle starts.  Bruce slams the door and awakens from his nightmare.  Used.