Brentilda Winkybunion is one of the four Winkybunion sisters but unlike the other three she is much nicer and beautiful.
Brentilda hides around various points around Gruntilda's Lair. Gruntilda is likely not aware of her presence, or is simply too lazy to deal with getting rid of her; thus she is free to run wild, working behind her back and pulling strings behind the scenes to get the duo to defeat her.
Every time the duo find her, she tells them three disgusting yet helpful facts about her sister Gruntilda, ranging from the name of her old boyfriend to her favorite color. Banjo and Kazooie use these facts for the "Grunty Square" questions on the Grunty's Furnace Fun board game. These facts are different for every save file, each having three variations (which are also picked at random at the time you'll hear them first), so the player must hear what Brentilda has to say in their own file for the facts to be of any use. Brentilda will also refill Banjo and Kazooie's health bar when they talk to her.
An interesting thing to note is a painting of Brentilda that is hung in the dining room of Mad Monster Mansion.
Brentilda is completely absent from Banjo-Tooie, nor is she even mentioned by the other Winkybunions. However, a portrait of Brentilda appears on the floor in Pawno's Emporium. This portrait is similar to the one previously seen in Mad Monster Mansion in the last game. The difference is that the one in Pawno's Emporium is rectangular, whereas the one in the Mansion was arched.
- Brentilda is an obvious parody of Glinda the Good Witch of the North while her sister Gruntilda is a parody of the Wicked Witch of the West.