Jim is the long-lost room-mate of Johnathan Gabriel and Tycho Brahe. He is currently a skeleton, as he died of starvation. Jim has a cameo in the video game, Penny Arcade Adventures: On the Rain-Slick Precipice of Darkness; his head floats in a fluid-filled jar in the offices of Startling Developments. It can be activated from the office, but all that happens is that the skull moves slightly and makes gurgling noises. In Episodes 3 and 4, he becomes a playable character, using his necromaster abilities to fight alongside Gabe and Tycho.
Jim wears a red t-shirt with a twelve-sided dice on it, with the throwing being a '1'. He also has a pair of blue jeans. It is unknown what his hair color is, as his living feature was done in black and white.
Now, at the end of the strip "Armadeaddon: Epilogue" in a photo Tycho kept, his hair is orange.
Jim used to try and get his room-mates, Gabe and Tycho, to play tabletop role-playing games with him or watch anime. He was even-handed, and slow to anger. According to Gabe, he is everything that Penny Arcade lacks.
It is possible that Tycho's fondness of the table-top role-playing genre spurred from Jim's behaviour with the game.
His death was untimely and was not even noticed until six years later. He entered the back of the television and tried to hook up the Nintendo 64, but died on his way over. Gabe and Tycho only found out when Gabe led an excavation behind it. He slowly died of starvation and soon turned into a skeleton.
As revealed in the Armadeaddon storyline, Jim, somehow, re-animated his skeleton, and became a necromancer due to it. He arranged the events within the mall to occur, as possible revenge for leaving him behind the television to starve to death. He still wears his red shirt, although his saving throw is now 20. After being defeated in initiative rolls, he and his undead crew are leaving. It appears he has also teamed up with the Zombie.