The StreetPass Bunny sells the DLCgames that can be bought for $4.99 each. You can also buy the first four games in a bundle for $14.99. She also made a bundle deal to buy Ultimate Angler and Battleground Z for $8.76. The bunny also appears to tell about the StreetPass Premium Update which costs $4.99; as well as the new DLC games bundle.
The Bunny's only appearance so far is the salesman for the eleven DLC games and the StreetPass Premium Update. A Wandering Hero summoned by another hero also takes the form of a rabbit, similar to the bunny. She mainly tries to get to you to buy the games, and she explains them in detail. She has a yellow tablet, with a black screen, and she uses it to show you screen shots of the game she is selling. The mii character playing the game is herself.
The bunny resembles a mii wearing a white dress and that has a rabbit's head.