|Classification||1/2 Human, 1/2 Demon|
|Age||Younger than Billy|
|Residence||Center of the Earth|
|Relatives|| Nergal (father)|
Harold (maternal uncle-in-law)
Gladys (maternal aunt)
Billy (maternal first-cousin)
Del Uglio (maternal first-cousin)
|Occupation|| Student at Endsville Elementary School|
Nergal's Pizza delivery boy
|Real world information|
|Appears in|| The Grim Adventures of Billy & Mandy|
Underfist: Halloween Bash
|First appearance||"Son of Nergal"|
|Voice actor||Debi Derryberry|
Nergal Jr. is the son of Sis and Nergal, and Billy's paternal first cousin. He has the ability to shapeshift, and has tentacles protruding out of his back and head, not unlike his father. He also possesses the capability to take the appearance of any human beings he chooses in order to impersonate them as well as the ability to freeze them in a state of suspended animation. Furthermore, he is able to take the appearance of any object. He is voiced by Debi Derryberry.
Nergal Jr. is referred to as a Nergal, which is a shapeshifting demon from the center of the earth. His mother, however, is human, making him a hybrid of sorts. It is never clear what exactly his true form is, for it has never shown fully on screen, but it can be assumed it is not pretty as it scared Billy into hating him briefly in the episode "Son of Nergal." And it may resemble his father. Because of his natural appearance he assumes the form of a little boy (nameless) he ran into in "Son of Nergal", it can be assumed that the little boy is still frozen in ice near the camp grounds to this day.
Nergal Jr. has an introverted personality. He has become used to people avoiding him and usually assumes the worst of other people, as see in The Greatest Love Story Ever Told where a little girl wanted him to walk her home but he shooed her away in the state of mind that the whole world hated him. Despite this, he, like his father, wants to have friends, though he can't seem to keep them longer than an episode.
Nergal Jr. is a half-human half-demon hybrid with black hair, pale skin and green eyes. He wears glasses. He wears a black shirt, black jacket, black pants, red scarf and black shoes. He wears a school uniform, consisting a white school shirt, blue pants and gray sneakers.
Nergal Jr.'s only friends are Billy, Mandy, and Irwin. Nergal Jr. and Mandy briefly dated in "The Greatest Love Story Ever Told Ever". It was an accident as the card he gave her was actually from Irwin, but she accepted it as an invitation from him instead. He confessed to his father that he wasn't sure he liked Mandy, but later on shouted at Irwin claiming he wasn't about to let the first girl that liked him for himself go away. Irwin and Nergal fought over Mandy only to realize that she didn't like either of them and was pitting them against each other. Afterward the two made up, indefinitely foreseeable as the incident was never brought up again. Billy was his first friend, but after seeing Jr.'s true form was frightened and briefly frozen for an episode. Afterward Nergal Jr. took the back seat and was only given lines in a few episodes, but other than that became a part of Endsville for the rest of the show as a background character. His only natural enemy is Sperg, the school bully who picks on him despite the obvious fact that he could send Sperg into a swirling vortex of doom for eternity. It is shown that at the end of one episode Sperg was Nergal's family pet just that one time.
Abilities and Skills
Nergal Jr. can shapeshift into any shape and form he desires at will, and paralyze enemies by ensnaring them in his snake-like tentacles. He can also walk through walls, fly with his own wings and create bats from his fingers.