The Hellstesses are henchwomen in the 2013 episode "Bot Seeks Bot" for the TV episode "The Venture Bros.", which ran on Adult Swim.
The Hellstesses act as waitresses in Don Hell's nightclub for villains. In addition, they distribute Torture Tickets which are in the form of plastic poker chips. These chips are used in the entertainment at the nightclub known as the Wheel of Torture. This is like a dark version of the Wheel of Fortune.
The Hellstesses are dressed in black goth type dominatrix costumes, including thigh high fishnet stockings and black boots. In addition, they have black jumpsuits, and one of them wears a choker necklace. Both women have existing tattoos and may or may not be vampires. Assuming Don Hell is a vampire, he did showcase some magical abilities not uncommon for a vampire.
Later the Hellstesses are shown assisting Don Hell in the torture of Billy Whalen and Dr. Rusty Venture. After spinning the wheel, and landing on "acid dip", they are about to help carry out the deed. However, the festivities are interrupted by The Monarch and Dr. Girlfriend, who free them.