narwhal

narwhal is a   Noun

Definition:

[1] An arctic cetacean (Monodon monocerous), about twenty feet long. The male usually has one long, twisted, pointed canine tooth, or tusk projecting forward from the upper jaw like a horn, whence it is called also sea unicorn, unicorn fish, and unicorn whale. Sometimes two horns are developed, side by side.

Synonyms: