Mousemallow
From PinataIsland.info, the Viva Piñata wiki
Statistics
Animal: Mouse
Candy: Marshmallow
Likes: Daisy, Turnip, Grass
Provides: ???
Attack: ???
Look at the little fella! Observation suggests those ears are for more than just show, which is just as well because there's no shortage of other Piñata keen to chase after the poor mite.