Dr. Beanies (full name Thomas A. Beanies) is one of the main people in Boon County. He is the first character the player interacts with, and is responsible for bringing them back to life. Dr Beanies is a extrovert, he also sometimes gets angry when you come up uninvited or do anything sudden. He appears as a white doctor with gray perked up hair like a mad scientist and he has round glasses. He wears a scientist uniform with dark gray glasses and he has brownish-blackish shoes. Dr. Beanies takes cats that have Mutations, Birth Defects, Disorders, or Parasites. He has like a billion clones of Stacy (his dead cat) roaming around in the county

Frank is "The sweaty sick thing in the sewers with all those rats". He provides the player with additional rooms for the house, in exchange for Retired Cats - cats that have gone on an adventure — for their services. Frank seems to be a naive and kindhearted creature, who often struggles with human speech. Their body seems like a hunched back-stitched together corpse, made with what appears to brown skin, with a cat tail and a living bean on top of his back.

Tracy Newkirk is the shopkeeper in Boon County. She is the clerk at Paw Mart (known as P Mart), where the player can buy food for their cats, as well as house upgrades and other items. Tracy is a pretty grumpy female. She often says to herself how she hates her job and everyone. She appears as a white woman with black hair with bangs, her hair could also be up in a bun. She also has a red headband with white polka dots on it. She also has a missing tooth on the bottom row of her teeth. She is wearing a blue short sleeved shirt with a maroon pin that says “NO” on it. She is also wearing gray sweatpants and black shoes. She takes cats of age 5 or above. For every 10 cats the player sends her, she will stock the P Mart with either a Food Storage Upgrade, a random Idol, or a blank collars

Organ Grinder (Also known as ??? or the Mystery man!!!) is an NPC in Mewgenics. He will automatically collect dead cats and attempt to retrieve items from lost runs. Organ Grinder has very limited memories, and routinely forgets topics of conversation. It seems he may have forgot even his own name, and names himself after the player's name. He appears as a rotten, greenish skinned man with only 3 strands of hair (???) on his head. He also has bandages that are going over his head and over his right eye. He also appears to wear damaged worn out coat, and black shoes.

Butch is a trainer. He upgrades the player's storage space, gives Class Collars, and provides commentary on new unlocks like chapters, classes and house bosses after receiving retired cats. Despite his tough exteriors Butch is a complex individual. Apart from his shady underground operations, he is surprisingly open about personal details, such as his family and his own existence. He also credits himself as being the former owner of and the one to personally train Guillotina before she disappeared. He wears a black mask, he has a mustache and he also has a dried scar on his left cheek, there also might be scars on his head too. He wears a black-gray shirt with a paw print on it, and he wears gray pants and black shoes.

Tink, full name Ferguson Rodney Tinkles, is the Cat Breeder. He accepts kittens (cats with an age of 1). In exchange for hitting a certain number of donated kittens he will upgrade the player's Ul, giving them insight into things like their cats' base stats, sexuality, etc. which helps the player better optimize the setup of their house for breeding. He mostly acts girly and twink-ish, he also loves to talk about his wife a lot, even though we never get to see her. Tink is a white male with light brown hair swept to the left. He has a pink shirt that can have different things on it and it has. short sleeves. He has dark lavender shorts on, and shoes the same color. (He is Butch’s twin brother, they used to be conjoined and when they were separated by Dr Beanies, they left a permanent scar on Butch and Tink’s face. But Tink hides it with Makeup.)

Baby Jack, full name Jackie Dustin Nickel, is a kid who sells furniture. He starts off by selling 2 pieces of furniture every week, and restocks on Sundays. He will upgrade his stock in exchange for cats with Injuries. He appears to be childish and very dumb. Baby Jack appears to be a short, white lid with short brown hair. He has a healed scar near his left eye, a bandage patch on his right eye, and he has a missing front tooth. He has a gray shirt, brown pants, and a black shoe on the left foot, the other is barefoot, and you can see a X shaped healed scar on his knee. He also wears a cast on his left arm.

Steven is a non-playable character. He primarily acts as an anti-cheat mechanism, but also becomes a regular NPC that can be visited. Later, he can be used to change the difficulty. He will not accept cats. He mostly jokes and acts rude, especially if you cheat. Steven is a void-entirely that is pure black and has a small head sticking out of the top-left side of his head. He has a white face, and so does the thing on his head.