After I started reading the book, I saw a picture of a Hellbender, which is a kind of giant North American Salamander, which looks like this: Bear in mind, I have lived for almost 57 years and never came upon a Hellbender Salamander till now.
Photo by: David Herasimtschuk
Then, a week later in the book, one of the people who are part of Hellbender indicated that the name was from the same amphibious source:
Delgado stared at the group with confusion. "Hellbender?" "It's a type of salamander." Doug explained. Delgado raised an eybrow. "A salamander?" "That's like a lizard...but wetter," Doug said. "I know what a salamander is!" Delgado shouted. "But why would you name yourself after one?" Doug looked confused, like maybe that was a trick question. "Because it has a really cool name."
Doug is right, it is a cool name. And we live in a simulation.