He is shirtless, in white underwear, and has plenty of red scratches, injuries, and rope-like burn markings all over his body. Around his neck is a noose, implying suicide, which Wendy drags like a leash.
He has a dazed-like expression, and moves and attacks on all fours like a dog, using no weapons other than his hands, which perform mostly lunge and claw-like attacks.
He is noticeably larger and bigger than a real human man, possibly symbolizing how Gregory looked to Jennifer when she was a child during the orphanage massacre: imposing, frightening and scary.
It is recommended to use the Lumberjack Axe against him in both encounters.
In the first encounter, the player can easily beat him by using the Lumberjack Axe.
In the second encounter, the player can either use the Lumberjack Axe again to kill him to achieve the bad ending, or use Gregory's Gun when he says "I'm sorry, Joshua" to achieve the good ending. He then proceeds to suicide.