Names: Gregory Guillemot-Guineafowl (née Guillemot), Gershon Guinn Guillemot-Guineafowl (née Guineafowl)
Other Names:
[Greg] Greg, Gregy, babe, hun’ (both by Gerson), Uncle Greg (by Gabby; sometimes by Gallus too), Mr. Guineafowl (sometimes by everygriff), Mr. Guillemot, kid, child, boy, sonny (all four by Grandpa Gruff)
[Gerson] Gerson, Gersy, babe, dear (both by Greg), Uncle Gersy (by Gabby; sometimes by Gallus too), Mr. Guineafowl (by everygriff), kid, child, boy, sonny (all four by Grandpa Gruff)
Gender: Male (both)
Residence: Griffinstone (birthplace, current residence)
[Greg] Silver Shoals, Cloudsdale (both briefly; formerly)
[Gerson] Rainbow Falls, Cloudsdale (both briefly; formerly)
Occupation: Traveling veterinarian, part-time assistant at animal sanctuaries and zoos around Equestria (Greg), Author (Gerson), Martial arts trainee (sometimes; both)
Relatives: Each other (husbands), Gabby (adoptive niece), Grandpa Gruff (co-parenting partner/ surrogate father/ teacher/ legal guardian)
Likes:
[Greg] Cooking, animals, helping others, animal caretaking, hard work, photography, picnics (especially with Gerson and Gabby), protecting Gabby, his husband’s novels, chicken lime soup, justice, Grandpa Gruff, Gerson’s free-spirit
[Gerson] Frozen food, Griffinscones, hard work, escargot, camping, spending time with Greg and Gabby, writing, getting inspiration, reminiscing his proposal/ wedding day/ adoption of Gabby, justice, Grandpa Gruff, big notebooks
Dislikes:
[Greg] Gabby getting hurt, animals in danger, mayonnaise, onion soup, separation from Gerson, Grandpa Gruff being mistreated/blamed for Arimaspi’s attack
[Gerson] Gabby getting hurt, running out of inspiration, being overwhelmed, seeing Gabby upset, separation from Greg, Grandpa Gruff being mistreated/blamed for Arimaspi’s attack, his editor (sometimes), Grandpa Gruff scolding him, usually for showing his work to Gabby before censors get to it - that’s because some of the stuff he writes about aren’t exactly considered “cub-friendly”
Age: 45 (both)
Personality:
[Greg] Caring, a bit overprotective, clumsy, a bit strict, serious
[Gerson] Level-headed, caring, protective, creative, free-spirited, chill, wisecracker
Kind: Griffon (both)
Distinctive features:
[Greg] Small marks on side of each eye, often seen with a stethoscope around his neck
[Gerson] Striped dark blue bandana accessory around neck, three scars on left leg, often seen with a fountain pen behind his ear
Cause of scars: Scratched up on a camping trip (Gerson)
Biggest Fears: Gabby in danger, separation from each other (all both)
Marital status: Married

Greg and Gerson are the married adoptive uncles of Gabby and two Griffons from the First Pack of Griffons Grandpa Gruff used to look after. Gabby loves her uncles, though they do get a bit overprotective of her (especially Greg), since she is their only child. They tuck her in every night, and are very attentive towards her. Most of the time, they will not let Gabby out of their supervision unless she is with Gallus or Grandpa Gruff. Still, since Gabby has grown up, they tend to be a bit more calm about their adoptive niece’s safety. The story of how they started taking part in Gabby’s custody is rather interesting:

One night when taking out rubbish, Grandpa Gruff found Gabby’s egg near one of the trash cans, damaged, so he took her in to patch it up. She hatched a few weeks afterwards and came into his responsibilities, since the elder didn’t know what happened to the baby’s parents. After spending a few days without properly naming the girl, Gruff decided to name her “Gabriela”. For the next few weeks, the old Griffon managed to cover the fledgling’s basic needs, although he soon realised that he was unable to take care of her constantly. Of course, there was no way he’d throw the baby away; that’d be way too heartless, even for him, whether he was Griffinstone’s toughest citizen or not. But, suddenly, an idea popped into his head: A short few years ago, Grandpa Gruff had found himself routinely invited to dinner by a Griffon couple of two male Griffons, Greg and Gerson, he’d run into and quickly recognised. He was very happy to see them after all these years as well as to find out that their childhood crushes on each other ended up in them being together, and was more than delighted to help when it came to popping the question. He also remembered them admitting to him that they’re seriously considering having a kid. The two were very caring and compassionate. He knew they were the perfect choice. Plus, he could have a kid that’s kind of his own, while not worrying so much about raising it badly. He introduced the little girl to the two Griffons. Greg was over the moon about meeting the giggly fledgling. Gerson was more hopeful for a baby boy, but he loved the idea of having a baby girl too. The couple couldn’t imagine WHY the little fledgling would be abandoned; she was the cutest, littlest, most adorable bundle of joy they’d ever seen! The two male Griffons happily accepted to help raise her and became her adoptive uncles.

Of course, before that, they first had to show Grandpa Gruff that they were capable of providing for the baby. That means they had to have stable jobs, a sound home, and time to take care of the child. Greg was a vet, and Gerson was an author, so those were jobs with good pay, and they already had their home. Though, due to them being pretty busy themselves, they and Grandpa Gruff, along with a few other adults around Griffinstone, take turns taking care of her, even to this day.