In the opinion of the late Rich Levad, the Black Swift was The Coolest Bird, and in his still-unpublished manuscript of that name, he advanced a pretty strong argument for its coolness. This is a bird that spends much of its time foraging so high in the air that nobody ever sees it. It nests in the spray zone of waterfalls, so that a juvenile may never have dry feathers between hatching and fledging. And it is poorly understood: to this day we really have nothing but educated guesses as to where the species spends the winter.
It appears that will change soon.