Hot Dog Water has been Velma's rival for years, as the two girls have competed several times in the science fairs in Crystal Cove and Velma has always won. However, their rivalry seems to have faded and has become friendship as a result of their partnership while working for Mr. E. They remain friends even after she leaves Mystery Incorporated, and Hot Dog Water claims Velma is the only real friend she's ever had. In "Wrath of the Krampus", Velma mentions that she still knows how to get in touch with her and she helps the gang by stealing the three pieces of the Planispheric disc from Mr. E's hiding place.
She has claimed to be smarter than Velma as she concocted a "super helium" during an experiment in which she was testing the metal from the roller coasters at her father's theme park. She also has high computer skills in which she is able to make fake advertisement sites, as well as accurate financial pie charts, though she cannot figure out the traps surrounding the piece of the Planispheric Disc in the ship during the episode, "The Night On Haunted Mountain" and causes the events to trick the gang, mainly Fred, into investigating the attack on Fred's friends, so Fred can trip the traps for her.
She is normally seen with messy, long brown hair, red slim-framed glasses, a skirt, stripped shirt with jacket over top and has a messy look about her. She smells of the "hot dog water", of which she got her nickname from, which her father reveals in "Menace of the Manticore" to be a result of she and her entire family bathing in recycled water previously used to boil hot dogs in.
Episodes: Where Walks Aphrodite, The Dragon's Secret, Menace of the Manticore, The House of the nightmare Witch, The Night the Clown Cried II: Tears of Doom!, Web of the Dreamweaver, The Hodag of Horror, Night on Haunted Mountain, The Midnight Zone, and Wrath of the Krampus.
- Hot Dog Water is voiced by Linda Cardellini, who played Velma in the two live action theatrical films of 2002 and 2004.