Common Loon

Gavia immer

Not named for being crazy. That sense comes from 'loony,' short for 'lunatic,' from the Latin for moon, though a raft of loons calling in the middle of the night, like a crowd of people whooping it up, may have helped. 'Loon' itself may come from the Old Norse lómr, for its call, or from a word meaning 'lame,' for how badly it walks on land.

Gavia was the Latin word for an unknown seabird; immer may come from a Norwegian name for the bird.