Grendel
The protagonist of the book. Grendel is depicted sympathetically, as a powerful adolescent seeking his place in the world, but whom no one can understand. The entire novel is told from Grendel's point of view, although Gardner uses Grendel's superhuman qualities to describe events and emotions that a first person narrator could not otherwise have realistically seen or perceived.
Grendel's Mother
A nearly unintelligent, bestial creature, Grendel's mother spends the entire novel lurking in her dank cavern home. She makes noises in ways that suggest she is trying to communicate to Grendel, but Grendel cannot (or will not) understand her.
Hrothgar
King of the Scyldings and founder of the mead hall Herot. Hrothgar begins his career as just another warrior, but his chance encounter with Grendel leads to a rivalry that boosts his reputation among his people. He is a political schemer who achieves his goals then finds them unfulfilling.
Wealtheow
Sister to Hymgod of the Helmings, Wealtheow sacrifices her own future happiness to marry Hrothgar, thus winning peace between her people and the Scyldings. Her very presence brings peace and joy to those around her, even though she herself is never truly joyful. Wealtheow is much younger than Hrothgar, a fact that does not escape the king as his powers fail him.
Unferth
A great warrior among the Scyldings, Unferth attempts to issue Grendel a hero's challenge. Grendel mocks him and drives him to the point of exhaustion, but refuses to kill him. Unferth then undergoes years of humiliation as an alleged "hero" who is not worth the effort of the monster to kill him.
The Shaper
A bard or scop, the Shaper brings history and fantasy together in his compelling songs. Grendel finds his glorified history of the Scyldings both enthralling and repulsive, and simultaneously seeks to avoid and fulfill the role the Shaper has given him as nemesis to Hrothgar.
Ork
An ancient priest of the Scyldings, Ork is surprised one night to find one of his old gods answering his prayers (although the god is really Grendel playing a role). Ork finds his philosophy of the King of the Gods affirmed by Grendel's lack of criticism and is thereafter considered either insane or ecstatic by his fellow priests.
Hrothulf
When Hrothgar's brother dies, the king is bound by duty to take in his nephew Hrothulf. He does so reluctantly, however, for in Hrothulf he sees his future usurper: a young man already influential and well liked, who is more fit to lead than any of Hrothgar's children. The old peasant counsels Hrothulf toward the violent overthrow of all governments. Hrothulf himself sees the need for the proper kind of government, and sees himself as the best leader for the position.
The Dragon
Encountered by Grendel when he happens to fall into its den, the dragon spouts existential philosophy at Grendel until he is able to get through to the seeking monster. The dragon claims to see past, present, and future simultaneously and declares to Grendel his role in the cosmos: Grendel is the opposing force against which humanity will sharpen itself into a great weapon. Grendel rejects this view, but falls into the role of Hrothgar's nemesis despite his personal objections. The dragon puts a charm on Grendel, making him immune to human weapons.
The Stranger
A foreigner who arrives on Hrothgar's shores with fourteen other mighty warriors, the stranger is obviously Beowulf. He is unlike all the Scyldings and poses a real threat to Grendel, for he needs no weapon to harm the monster. The stranger is the agent of change in an otherwise cyclical world.
