Why does beowulf have to kill grendel? ?

Beowulf states that he will fight Grendel without armor or sword, hand to claw, because the ogre does not use weapons. If Beowulf is killed, he wants his war-shirt (breast armor, mail) returned to King Hygelac. Hrothgar offers a joyful feast in honor of Beowulf's arrival.

Their battle concludes with Beowulf's ripping Grendel's arm off, fulfilling his promise to Hrothgar to kill the monster with his bare hands. Beowulf nails Grendel's severed arm to the mead hall rafters and, although Grendel runs away, he is later found to have bled to death in his underwater lair.

Explanation:

d. murder of a son and cooking the son for a feast

procne murdered her son and served him to tereus, her husband and her son's father. she did this out of revenge. tereus raped her sister, philomela, and cut her tongue out to keep her from talking. philomela managed to communicate it to procne and procne sought revenge.

tantalus murdered his son and fed him to the gods because he was angry with the gods. the gods punished him by putting him in a pool of water that evaporates when he tries to drink and having fruit hang just out of his reach.