This quest is found in the BeowulfArea.

Obtain the fishshape. Find a goose in Geatland, KILL GOOSE, GET FEATHER CORPSE. WEAR FISHSHAPE, HUNT BEHEMOTH (You need sustained breath). When the whale sees you in the fishshape, it will eat you. You are now in the whale's belly. TICKLE WHALE and you and Beowulf will be spit out upon the Pebbled Beach, where Beowulf will declare you to be his companion!

-> you'll get the whois ...IS KNOWN TO BE A COMPANION OF BEOWULF!