Thin and XL (no relation) are two pirate/treasure-hunting mice; Thin is the skinny mouse, and XL is the chubby mouse. They escaped from a vicious cat from the same ship their friend Winner ran away from and they have lived in the Jungle ever since. Their ongoing dream is to be rich and find loads of treasure, although they tend to get into mischief and have a tendency to steal others' property. They seem to be scared easily, but they have warm hearts to their allies and each other.
As Simba, Buckshot, and company escaped from Shere Khan through the Valley of Time, they wound up in the Nile. While they made recruits, the mice explored some ancient Egyptian ruins. A mouse guide led them to Ratsy's Tomb. Having the exact measurements upon a crystal scale and through a time tunnel they beheld their 3,000-year ancestors, Pharaoh Ratsy and Queen Cheddarisis. It was from them that they received the sacred amulets, which allowed Thin to see his friends in danger from faraway, and XL to conjure needed items, mostly food and drink, on a whim. Near the end of the first series, they eventually had the ability to teleport by pressing a button on them.
In the second series, they get involved in a search party to find Winner who's been taken to NY by humans. They seem to be rather ecstatic returning to the city, even calling it "a home away from home."
Eventually, they find Winner who happens to be a soccer coach for the Animal World Cup; they join as Team Africa and later win the tournament along with Simba Junior and his young comrades.
Not much of them were seen in Winner and the Golden Child, excepting in the last few episodes. They had been residing and having fun in the flower garden where Simba and his family were, excepting Light, along with Flash, Simba Jr., Pinball, as well as the other juniors. They witnessed Ari and his team win over Shere Khan and Maya in a soccer tournament. Then, they visited Ari's new home in the Singing Valley.
Thin and XL may seem to be dastardly due to their size, but they're quite a friendly pair; however they can also get mischievous if the desire for treasure or food should arise.
Thin is the skinny mouse wearing the blue-striped garb embedding with his name in bold, while XL is the chubby mouse wearing the red-striped garb embedding with his letters in bold. They each have light grey fur and white sailor hats, though their black pants are in different sizes.