The largest and most specialised of the aviserpents that feeds on shoaling cephalopods, particularly larval balaenateuths that often swarm around the New Zealand coast. It slowly cruises near the surface, snapping it's long neck from side to side as it seizes prey.

    The nest of the monarch aviserpent is unique amoung the animals of Spec. Both parents construct a conical "fort" of small rocks up to 5 m across at the base and 1 m high. At the apex, a single egg is layed in a shallow depression lined with decaying seaweed. The parent's take turns in sitting atop this structure to incubate the egg.

    The monarch aviserpent's range is centered around New Zealand, with occasional specimens turning up in Tasmania, Lord Howe and Norfolk Island. It's distinctive serpentine silhouette is a common sight in the Cook Strait.