"Winona" is a name of Native American origin, meaning "first-born daughter".[1][2] In both behavior and appearance, Winona resembles a Border Collie, which are natural animal herders.
According to Lauren Faust, her name was originally "Brandy", then "Buckaroo".[3]
Winona is first introduced in Applebuck Season, helping Applejack round up the stampeding herd of cattle that is heading towards Ponyville. Later in the episode, Applejack has a tough time helping Fluttershy round up some bunnies, so Applejack tells Winona to help her, causing the bunnies to stampede towards Ponyville like the cattle did.
Winona is also briefly seen in May the Best Pet Win! in Rainbow Dash's dream, where Owlowiscious's head transforms into Winona's, and during the pony pet playdate. She also appears in The Last Roundup, where she greets Applejack as soon as she steps off the train at the end of the episode. In Ponyville Confidential, a photograph of Winona as a puppy is briefly seen depicting her pulling at a young Apple Bloom's diaper. This is a parody of the original Coppertone ads.
Winona later appears in Just for Sidekicks as one of the pets Spike petsits in exchange for a jewel. Here, Applejack claims Winona gets wild if she doesn't get her daily exercise, and is also shown to greatly enjoy getting belly-scratches from her owner. When the Cutie Mark Crusaders briefly take over watching the pets, she becomes the participant of the industrial-size pet hair dryer they had purchased with one of Spike's gems.