The holographic king of the Danes in Harry Kim's Beowulf holonovel, whose hall is terrorised by Grendel when a photonic lifeform takes over the programme.
Hrothgar is a character in a holodeck adaptation of the Old English poem Beowulf, written for recreation by Harry Kim. He appears in the first-season Voyager episode Heroes and Demons.
Hrothgar rules from his great mead hall, where his warriors live in fear of the monster Grendel. When Kim, and then Chakotay and Tuvok, vanish inside the programme, the Doctor is sent in on his first away mission and is presented to the king as a hero come to deliver the hall.
The weary monarch has seen many champions fail and holds out little hope. His court also includes the shieldmaiden Freya and the suspicious Unferth. Grendel proves to be a photonic being reacting to the capture of its kin, and the Doctor wins his crewmates back by returning it.