Gregory is an old mouse/rat who serves as an antagonist in the anime Gregory Horror Show and the video game Gregory Horror Show: Soul Collector. He is the propietor of the mysterious Gregory House, where lost souls end up.
He acts as the manager of Gregory House in the first two series "The Nightmare Begins" and "The Second Guest". As the manager, he frequently saves the two unseen protagonists of both series from being killed by the various residents, bringing them back to Gregory House. It's ultimately revealed in The Second Guest that he is securing lost souls within Gregory House for his mother, Gregory Mama, who uses the souls to revitalize herself.
One of Gregory's more villainous acts is the imprisonment of a cat called Neko Zombie, who he starves and locks up under the pretense of Neko being dangerous. It is heavily implied that he was the one who rendered Neko Zombie into his current state. Neko Zombie ultimately burns down Gregory House at the end of The Second Guest in an attempt to kill Gregory and Gregory Mama and end their schemes. His attempt proves to be in vain, as Gregory and Gregory Mama resurrect and make the eponymous second guest into a member of their family.
The third series The Last Train features Gregory in a Protagonist Villain role, where he is a passenger aboard an unusual train populated by Gregory House residents and other monsters. Throughout that series, he offers advice to a few characters about overcoming their obstacles to achieve their dreams, such as encouraging two Dead Bodies to be daring to escape their retched existence and two Trap Mice (robotic mice with oversized mechanical jaws atop their heads) to fight their instinct to attack whatever comes near them in order to be together. He then chuckles at their disastrous outcomes (one Dead Body is killed by an open window's air shattering him apart and the Trap Mice destroy each other when they can no longer fight their instincts). He also appears a few times in the fourth and final GHS series The Bloody Karte as a recurring patient at Catherine’s hospital.
In the beginning of the game Soul Collector, Gregory welcomes the player character (who will be male or female depending on player choice) and gives them a room. He warns the player character not to interact with Neko Zombie. He is one of the few residents who will not harm the player through a "Horror Show" (a staged event where a hostile resident does damage to the player) as the player goes around to collect the souls held by the various residents.
As the game progresses, it is revealed that Gregory is trying to entrap the player character's soul so that they can be used for Gregory Mama's revitalization (as in The Second Guest). By the end, the player character foils their plan by releasing all of Gregory Mama's captured souls. After tricking Gregory Mama into destroying the door to the real world with her magic attacks, the player character goes to the real world and is pursued by a spectral Gregory, who tries to convince the player that the real world isn't worth returning to. The player returns to rescue Neko Zombie, who aids in the player's escape by burning down Gregory House (as he did in The Second Guest). Unfortunately, Neko's efforts were once again in vain, as the player character decides that they will remain in Gregory House. Gregory is resurrected as Gregory House rebuilds itself and he escorts the player back to their room.
Gregory has an obsession with ensuring that those who take up residence in Gregory House become permanent residents. He also demonstrates an unusual habit of appearing out of nowhere and is known for his chuckle, which usually comes up when he's lying. Generally good-humored, he is none the less determined to keep residents from leaving. Sometimes, it is said that he himself is a symbolic manifestation of people's desires, such as wanting to escape "cold, harsh, boring reality" for something more.
Despite his villainous qualities, he's also often the victim of physical abuse, particularly from his mother, who frequently raps him on the skull with her staff. He utterly loathes his mother, but will do her bidding out of total fear. He also suffers abuse from other characters, such as the Roulette Boy section of Soul Collector where he'll be pitted against the player character and possibly subjected to getting crushed by (giant) weights as much as the player character.
He's also a bit of a pervert, as seen with his possession of two dirty magazines in Soul Collector. One episode of The Bloody Karte revolved around James discovering one of Gregory's dirty magazines and blabbing about it to Gregory Mama, who then beats Gregory for it.