As a human, Gladys is a short and obese woman with brown hair combed over her head, dressed in a green tage and a brown suspender.
In her true form, she is a big fat troll with yellow skin, hair pulled up with a bandana, an old dress and a green skirt.
Gladys initially appears as a minor character who works as a assistant of Toby's dentist. However, in "To Catch A Changeling", when Jim and Toby decide to discover the Changelings in Arcadia, Toby takes an gaggletack with Dr. Muelas since he was convinced that he was a Changeling. However, the Changeling turns out to be Gladys who silk Toby with a paralyzer and forces him to tell who else knows about the Bridge or the Changeling. Blinky and AAARRRGGHH!!! arrive to help Toby and Jim finally kills Gladys with the Sword of Daylight.