Madame Foster is a fictional character from Foster's Home for Imaginary Friends. She was voiced by Candi Milo.
Madame Foster founded the home that bears her name. She's had a strange life, having once gotten lost in the house for a week, eating nothing but acorns and toothpaste. She also spent forty-six days in the horse stables when her granddaughter Frankie accidentally let the Scribbles out from the forbidden door in the cold autumn of 1984. She owns what looks like a late 1970's Pontiac Trans Am sports car, complete with the "screaming chicken" on the hood similar to the one shown in the Smokey and the Bandit movies, which she likes to drive around town. She has a long-standing feud with the neighbor across the street, Old Man Rivers. According to her, Rivers borrowed a cup of sugar from her in 1962 "and did not return one single granulatory ounce!" However, Rivers has a secret crush on Madame Foster that he eventually reveals to her. She also possesses a chest of pirate treasure buried near a hydrangea bush on her property.
When Madame Foster was a child, she created her first (and apparently only) imaginary friend Mr. Herriman, a giant rabbit who wears a top hat, a monocle, a vest, a bow-tie, and a mustache while speaking in an English accent in a personification of the Edwardian era. Herriman would often perform for the younger Madame Foster, doing an assortment of dances and songs, which he continues to do to this very day, much to his own slight embarrassment. Much like with the series main characters Bloo & Mac, Madame Foster and Mr. Herriman are polar opposites. While Madame Foster is kooky and full of energy, Herriman is reserved and obsessed with rule following. However, their friendship remains as strong as it ever was, particularly in the fact that even as Madame Foster grew, she never gave away Mr. Herriman like so many other children did with their own imaginary friends. When at last Madame Foster created her foster home for imaginary friends, she made Mr. Herriman the president of the house, in charge of running the home and handling the adoption of the friends.
In later years, Madame Foster would take in her granddaughter Frankie Foster. Frankie would stay with her grandmother throughout her own childhood and into her teen years, and would later take on the role of 'estate manager' and caregiver towards the friends.