In Hilton's limo, Tinkerbell uses Hilton's cellphone as a distraction while she gets the driver's revolver, the gun which she uses to commit suicide with. Afterward, Tinkerbell is "replaced" by Mr. Biggles (Butters).
Tinkerbell has dark brown fur with a light blue bow tie, a teal gemstone necklace, and dog shoes. Her appearance is a direct reference to how Paris Hilton dresses up her dogs as if they were fashion accessories instead of treating them like actual pets.
As with all of Paris Hilton's other dogs, Tinkerbell had committed suicide. This was because she lived miserably being Paris's fashion accessory.