Other Names: Grandpa Gillan, Gillan, Gills (by his friends and frenemies), Honey (by his wife), grandpa (by his grandchildren), troublesome fella (by Grandpa Gruff), Featherbrain (by Grandpa Garvey)
Gender: Male
Residence: Griffinstone
Occupation: Orange Grower, Salesgriffon
Relatives: Unnamed wife, unnamed daughter, unnamed son-in-law, Gunner (grandson), other unnamed grandchildren
Likes: Causing trouble, making orange juice, sports, challenges, making fun of Gallus and Grandpa Gruff, annoying Gruncle Gonsod
Dislikes: Being in trouble, humiliation, Gunner assuming he doesn't love him
Age: 68
Personality: Confident, sneaky, mischievous, proud, a bit boastful
Kind: Griffon
Distinctive features: Collar accessory around neck, scars on right eye
Cause of scars: Scarred by cub Gallus while making fun of Grandpa Gruff
Biggest Fears: His wife's anger, Gallus (briefly/ formerly)
Marital status: Married
Grandpa Gillan is an old Griffon from Griffinstone and one of the Senior Group's frenemies. He's also the grandfather of Gunner and his siblings, and father of his grandkids' mother. He's also best friends with Grandpa Garvey and Grandpa Gino, the grandfathers of Gunner's best friends. He works as a salesgriffon, growing and selling oranges, along with his family. Gillian and his friends (sometimes accompanied by their grandkids) all feel bitterly towards Grandpa Gruff and make fun of him and Gallus constantly, for many reasons, including their lack of family, their appearance and their 'softer sides'. They mock them incessantly and do everything they can to get under their skin. They often refer to them as "Gawk-lose" and "Grandpa Gasbag", something that's later mimicked by their grandkids. However, when realising that Gallus ran off (back when he was a cub) and how important he is to Grandpa Gruff, their view on the two Griffons slightly changes and they start to be a bit more sympathetic towards them. Gillan was the first to have a change of heart. The Griffon he gets into fights mostly with is Gruncle Gonsod. Both being salesgriffons, Grandpa Gillan and Gruncle Gonsod are always at each other on who is the best grower or who takes better care of their harvests. Gillan finds amusement in gibbering Gonsod by saying that Griffons rightfully choose his 'ginger goodnesses' (oranges) instead of Gonsod's 'bleak bronzes' (carrots), which is usually enough for the other Griffon's blood to boil. However, despite usually being confident, Gillan acts rather cowardly every time his wife catches him doing similar actions.