The Master of Whistles (also known as Teapot in the credits) is a minor character who appears in the episode "Mouth Hole". She aids Robin in his quest to learn how to whistle. She is voiced by Tara Strong.
Robin, disappointed at his lack of ability to whistle, was sent on a journey by Raven to the Mystical Mountains of Gamera. Here, Raven said he would be able to learn to whistle from the Master of Whistles.
Some time later, Robin arrived at a medieval-style castle in the middle of a blue mountain range. As he entered, he was frightened by a small teapot. At first, Robin was just annoyed by the teapot, but he soon figured out (after cruelly being blasted with an enormous whistle) that this was the one he was searching for - the Master of Whistles! Robin begged for forgiveness for underestimating her, so she gave him a small drink from a teacup. Inside the cup was hot sauce, which of course agonized Robin; however, at the same time, his doubt was unblocked.
And so he began his grueling whistle-themed training. Teapot made him blow at rocks, lift pebbles with his mouth, and even tried to break a piece of wood with a whistle-fist. Unfortunately, Robin just wasn't getting it. The training intensified, and when the Master launched rocks at him, Robin was able to deflect one back with a whistle. He could now complete all the tests, lifting boulders with a mere whistle, flinging stones around, perfecting the whistle-fist.
As the Master of Whistles complimented him on his work, Robin received an alert that his friends were under attack. Teapot argued that he is not ready to save them and attempted to whistle-punch him. However, Robin's whistle-fist was overpowering, and the Master of Whistles admitted that he was ready and sent him off to rescue the other Titans.
Near the end of the fight, Robin was fending off a giant laser from Gizmo's Death Ray with whistle energy, but it was too strong for him. Suddenly, an apparition of the Master of Whistles appeared to him, reminding of his "steam" power (from when he drank the hot sauce). Robin was then able to win the standoff and destroy the contraption thanks to Teapot's help.
The Master of Whistles is a small, white teapot, probably with some tea in her. She has a hot pink lid with golden edging, along with a golden handle. She resembled a fancy teapot.
- Power Whistling: She has the ability to fought her opponents by whistling.
- Mouth Hole (debut; only appearance)
- The Teapot Master was inspired by Mrs. Potts from Disney's 1991 animated classic film, Beauty and the Beast.
- The chipped teacup is also a reference to Chip from Beauty and the Beast.