The leader of Niddhoggr is referred to as 'Sir' (
Nidhoggr's squads are named after human body parts in German, such as the Nase ('Nose') platoon operating in Nord Highlands during the Erebonian Civil War on behalf of the Noble Alliance or the Magen ('Stomach') battalion involved in the attempted assassination of Prince Albert von Bartholomeus during the Trilateral Summit in Crossbell on behalf of Count Jerome von Bartholomeus.
Former Nidhoggr squad leader Nacht Weiss says that Nidhoggr owes its invincibility and naming structure to the dissatisfaction in the world: every time one of Nidhoggr's squads get disconnected from the main body, such as an 'Arm' or a 'Leg', it is being regenerated by people upset with the society, criminals and other jaegers in the world.
- Magen batallion
- Linken Arm regiment
- Nase platoon
- Kleiner Finger platoon
- Airi Adler
- Nacht Weiss (former)
- Aika (アイカ), Hugo (フーゴ), Klein (クレイン), Jan (ヤン) and Gastea (ガステア) appeared in one of Nacht's flashbacks. They are former members of Nacht's squad who got killed in action.
- Nidhoggr might owe its name to the horrific monster in Norse mythology, Níðhöggr, which was said to chew on the corpses in the afterlife.