The epic of Beowulf tells about the life of the epic hero Beowulf. Over the course of his life, Beowulf battles many different beasts and monsters. Beowulf speaks of five different monsters or beasts which Beowulf must fight.
Grendel--This is the monster attacking Hrothgar's mead hall (Heorot). Beowulf hears of Hrothgar's problem and travels to the Danelands to defeat the monster.
Grendel's mother--Grendel's mother, after attacking Heorot and killing Aeschere (Hrothgar's right hand man) in revenge for her son's death, fights Beowulf. Beowulf, after Hrunting fails, uses the sword of a giant to kill Grendel's mother.
Water Monsters/ Sea Beasts--Readers see these creatures twice, once in Beowulf's swimming challenge with Brecca and once in the den of Grendel's mother. Therefore, these creatures are counted twice. In his swimming challenge, Beowulf killed nine water monsters. In his battle with the sea beasts in Grendel's mother's den, Beowulf came across "many" of the beasts. An exact number is not given.
Dragon--The dragon was Beowulf's last foe. Although he is able to defeat the dragon, with the help of Wiglaf, Beowulf's injuries are fatal. This is the last time Beowulf will fight.