"Gila monster"
Gila monster
Creative Commons Attribution Share AlikeGila monster - Credit: Blueag9
A heavy, slow-moving, poisonous lizard (pronounced “HEE-la”) native to the southwestern United States and northern Mexico. It is so sluggish that it poses little threat to humans, but hikers and homeowners still sometimes kill it, though it’s protected by the state laws of Arizona and Nevada. Its skin is formed of beaded scales, in a variety of colors (blue, hot pink, silver, orange, and yellow along with the predominant black banding and mottling) that can be surprisingly vivid.

The narrator refers to the Dust Witch’s “Gila monster neck,” which may imply that it’s very dry, rough, wrinkled, and spotted. The connection to something sluggish and poisonous works, too.