The octopus was a pet or familiar of Muturangi, a powerful tohunga of Hawaiki. The wheke was nonetheless a wild creature and a guardian.
When Kupe reached New Zealand, he encountered the beast off Castlepoint. The giant octopus then fled across Cook Strait, and was chased by Kupe through Tory Channel. Here a great battle took place, and when the octopus appeared to be about to flee, Kupe cut off its arms with his adze, killing it (Tregear 1891: 184, 620).
In the traditions of the Ngāti Ranginui people of Tauranga, Te Wheke-a-Muturangi was killed by their ancestor Tamatea, and is not associated with Kupe. New Zealand ethnologist David Simmons has suggested that this may be the more authentic tradition, and that the association with Kupe is found only in problematic sources (Simmons 1976).