Princess Sally Alicia Acorn is a character created for the Sonic the Hedgehog video game franchise. Based loosely off of the little squirrel who appeared as a supporting character in the early games, she originated in the Saturday morning animated series spun off from the games (nicknamed Sonic SatAM by fans), in which she was the princess of the city of Mobotropolis, whose father had been exiled by Dr. Robotnik. To combat Robotnik, Sally was the leader of the Freedom Fighters, a group of rebels which Sonic the Hedgehog, her close childhood friend and eventual love interest, was a member of. Sally would also appear in the Sonic the Hedgehog comic book published by Archie Comics and on various western Sonic merchandise in the 1990s, despite never being incorporated into the games themselves (except for cameos in the first and third bonus stages of Sonic Spinball).
Sally only briefly appears in the franchise's Christmas special, Sonic Christmas Blast, even though she had never appeared before in Adventures of Sonic the Hedgehog, the series that the special was spun off from. This makes the special Sally's only appearance in that particular continuity, though whether this version of Sally shares the same background details as her counterpart from Sonic SatAM or the comics is never mentioned. Early on in the special, she and Sonic "agree" that they will not get each other Christmas presents this year. Immediately following this, Sonic explains to Tails that he and Sally made this same agreement last year, but while he actually took the deal seriously, Sally actually did give him a bunch of presents, including a ring with a mysterious squiggle mark. Therefore, Sonic has figured out when Sally "says she wants no presents, she really means two stores full."
Unbeknownst to Sally, the ring that she gave Sonic last year enables him to unlock ultimate velocity through a series of tests, which allows him to retrieve all of Santa Claus' presents that were stolen by Robotnik and his Badniks, and then distribute them all over Mobius. As a result, this means Sally provided a major impact on the story despite her limited screentime. Sally is seen again at the end of the special, when Sonic, in the midst of distributing Santa's gifts, shows up to deliver her presents, and also holds a sprig of mistletoe above her head and gives her a kiss.
It is worth noting that, except for an audible gasp provided by Tabitha St. Germain, Sally never actually has any dialogue in Sonic Christmas Blast. A brief cut right after Sonic speaks with Sally at the beginning suggests that dialogue for her was already scripted and even animated, but was cut out because Kath Soucie (who had voiced Sally on Sonic SatAM) was unable to reprise the role due to her contractual obligation of voicing Lola Bunny in Space Jam.