Grendel is a character in the Anglo-Saxon epic poem Beowulf . He is one of the poem's three antagonists , all aligned in opposition against the protagonist Beowulf. He is referred to as both an eoten and a þyrs, types of beings from wider Germanic mythology. He is also described as a descendant of the Biblical Cain and "a creature of darkness, exiled from happiness and accursed of God, the destroyer and devourer of our human kind." He is usually depicted as a monster or a giant, although his status as a monster, giant, or other form of supernatural being is not clearly described in the poem and thus remains the subject of scholarly debate. The character of Grendel and his role in the story of Beowulf have been subject to numerous reinterpretations and re-imaginings. Grendel is feared by all in Heorot but Beowulf, who kills both him and his mother.