These birds make a very good tame for a variety of reasons:

Firstly, as combat pets: working similar to a dimorphodon but underwater, capable of taking down even the largest creatures in a swarm, and also being able to wear hats for extra protection.

Secondly, as egg animals: their egg is as light as a dodo egg but slightly better food, and they're much easier to find than dodos in the snow.

Thirdly, as heating: they are brilliantly insulated to the point that they actually overheat even in their snowy home and radiate warmth, useful for keeping warm or hatching eggs.

Fourthly, as companions: they make good pets due to their appearance and ability to wear various hats