Narwhal are relatively small whales (16~18ft or so) that live entirely way up in the Artic.
They very rarely breach the water surface beyond just their backs sticking up or the occassional tail (below).
Narhwal are one of the more amazing whale species because the males grow one large tusk then look like unicorns.

Just outside Baffin Bay near Pond Inlet, Canada
June 2018