The Green Sprixie Princess is a Sprixie from Super Mario 3D World.
Green Sprixie appears in Stupid Mario 3D World, where she appears out of a clear pipe that Mario discovered and fixed. She asks him and his friends for help, as Bowser is hunting her down to capture her, but they're too busy debating what she is. This allows Bowser to capture her anyway, as he wanted to get Bowser Jr. a leprechaun for his birthday.
She is eventually rescued by Mario and his friends, but then tells him that there are six more Sprixies to save. Much to Mario's frustration, he decides to sell her to the Happy Mask Salesman.