Beluga Delphinapterus leucas (VU) and narwal Monodon monoceros visit Disko Bugt in autumn and winter.    From Wordnik.com.  [Ilulissat Icefjord, Denmark-Greenland] Reference

In the sea are found the black whale, porpoise, sea-horse, seal, and the narwal or sea unicorn; the horn of the latter, solid ivory, is a beautiful object.    From Wordnik.com.  [Notes of a Twenty-Five Years' Service in the Hudson's Bay Territory Volume II. (of 2)] Reference

I think he's actually a narwal trapped in a man's body.    From Wordnik.com.  [The Guardian World News] Reference

The handle is sometimes made of the horn of the narwal, but more frequently of wood.    From Wordnik.com.  [Ungava] Reference

Apply Gilette Fusion gel, scented with sandalwood and the essence of narwal bladders, (£4 a can).    From Wordnik.com.  [Army Rumour Service] Reference

They used it for pointing their spear-heads and harpoons, which, in default of iron, were ingeniously made of ivory from the tusks of the walrus and the horn of the narwal.    From Wordnik.com.  [The World of Ice] Reference

"There hunted 'she' the walrus, the narwal, and the seal.    From Wordnik.com.  [A Holiday in the Happy Valley with Pen and Pencil] Reference

No satisfactory use has been assigned for the horn that arms the male narwal, nor should any reason be conjectured for its presence that involves its possessor's mode of procuring food, since the same necessity would be unprovided for in the female; yet I have sometimes thought the horn was employed to dislodge the flat-fish, on which the unicorn feeds, from the recesses of the bottom, where they would naturally conceal themselves at the sight of their enemy; and if the narwal seeks its prey in company, as, from its constant appearance in a shoal, may be concluded, the raking of the horns amidst the weeds and ooze would be as serviceable to the unarmed females as to their gallant consorts.    From Wordnik.com.  [The Mirror of Literature, Amusement, and Instruction Volume 13, No. 367, April 25, 1829] Reference