In Maori legend, Pouaki is a monstrous bird that hunts for people and livestock. Its predations were ended by the cunning plan of the hero Hau-o-Tawera who caused his people to fashion a great net in which to trap the bird. Waiting in hiding, they baited the trap and entangled Pouaki in the net while stabbing it to death. A similarly named bird, Poukai, who may be the same being, is similarly trapped by a pair of hunters led by Pungarehu who travels into the Otherworld after many people have been taken away by it. They chop off the bird's wings and find the remains of their fellow villagers, but on their return they find that all their relatives have died or become much older, since their time in the Otherworld was longer than they had imagined.
I've decided to create a burly, muscular looking monster that looks strong enough to carry people away. I referenced some shark elements as part of a lot of Maori environmental threats, built around the body of a golden eagle, and shaped the wings like those of a sleeker seagull.