The Nameless One is the source of all evil and also the ultimate antagonist of the Dungeons & Dragons TV series. It is described by the Dungeon Master as pure evil and is Venger's master. He appears as a giant column of green flame and his face is said to be something not meant to be looked upon.
The Nameless One's only appearance is the episode "The Dungeon At The Heart of Dawn", where it is summoned by Eric after he opens the Box of Balefire. Upon arriving at the Realm, Venger decides to greet his master, but is chided for his repeated failures to kill the children. Afterwards, the Nameless One sets out to kill them himself, rendering Venger powerless in the process.
While traveling to their next destination, the kids feel the wind suddenly picking up. Horrified, the Dungeon Master senses the Nameless One approaching them. So he teleports the kids and himself across different places across the Realm, only for the Nameless One to catch up. In the midst of this, the Dungeon Master explains that the Nameless One is the ultimate evil and "not life as we know it".
After exhausting most of his energy, the group decides that they will run no further and try to fight the Nameless One instead. Using the power of the kids' weapons, the Dungeon Master tries to fight him, but is effortlessly overpowered. Using the remainder of his power, he teleports himself and the kids to the Underworld, but loses almost all of his power in the process.
The Nameless One is never defeated and simply leaves the Realm for other worlds to terrorize.
- The Nameless One is briefly mentioned in the unfinished series finale "Requiem".
- Due to its unfathomable and mysterious nature, it is possible that the Nameless One is an obyrith. A type of demon known for its maddening nature. Or even an Elder Evil, a similarly Lovecraftian being in the D&D mythos.