Raoul Moat likened himself to King Kong and the Incredible Hulk while on the run from armed police.
The gunman said he struggled to contain his murderous rage and that he “hated himself” because of it.
The feelings could have been triggered by a traumatic childhood in which he was beaten and once saw his mother burn all his toys, an inquest at Newcastle Crown Court heard.
A jury heard the fugitive was paranoid, suspicious, mistrustful of authority figures and blamed other people for his misfortune.
But he was not mentally ill, according to a forensic psychologist brought in to advise expert police negotiators.
Moat shot himself after a tense six hour standoff with armed police, in Rothbury, Northumberland, last year.
The inquest heard Moat was tormented by bad dreams and feelings he struggled to control.
He detailed how they affected him in recordings made on a dictating machine while he was on the run following the shootings of karate instructor Chris Brown, his ex-girlfriend Samantha Stobbart, and Northumbria Pc David Rathband.
He said: “I feel like King Kong when he’s right at the top of that building, all messed up, when he’s in a real mess.
“I hate myself. I do hate myself.
“It is a part of me. I’m like the Incredible Hulk.
“It is not anger, it is something completely different.
“It is just like a wild animal, and it’s been there all my life.
“I’m not sure if my parents put it there or if it has always been there.
“I’ve had it at the back of my mind and it only ever comes out when I get hurt.
“It is just bonkers.
“A psychologist said it has got something to do with my mother and rejection; I don’t know, I don’t understand that kind of thing.”
He said the violence he’d committed “did not feel real” and likened it to playing the shoot ’em up video game Doom.
And he said when he shot his victims his jaw had been “champing, like he was on ecstasy”.
Forensic psychologist John Hughes said the recordings showed Moat “ruminating and rehearsing” what had happened in his mind, as he tried to make a decision on his next move.