Nadine Flumberghast is the imaginary friend of D.W. Read and a character in the PBS Kids cartoon Arthur. She was introduced in "D.W.'s Imaginary Friend" in the series, although she appeared in "D.W.'s Baby", which is a prequel to that episode. Her full name is given in "Read and Flumberghast". She is voiced by Hayley Reynolds.
It was revealed in "Read and Flumberghast" that, because Nadine is imaginary, she has special powers. She created ten copies of papers by just widening her eyeballs, and made two drinks for her and D.W. with a snap of her fingers. This is the first time this has been recognized. Also, in "Mom and Dad Have a Great Big Fight", she is able to control time by rewinding, pausing, and unpausing the episode, as well as being one of the few characters to break the fourth wall outside of the intro to an episode.
In contrast to D.W., Nadine is calm and soft-spoken. She often gives D.W. advice, though she rarely takes it, and she often only appears when D.W. is alone or when she thinks nobody is watching her.
- Her name could be based on the Spanish word nadie, which means "nobody" or "no one", referencing the fact that she is imaginary.
- She and D.W. virtually have opposite personalities, but they get along really well.
- D.W. invented her when she was three.
- She is featured in the song "Has Anybody Seen My Invisible Friend?" on the album Arthur's Really Rockin' Music Mix, in which D.W. claims that she's lost her and asks a group of kids to help find her, even though nobody but her can see her.
- Nadine states that she thinks that D.W. is getting too old for her, but D.W. continues to call upon Nadine.