KJV rendering for an animal called a “wild ox” in the nlt and most modern translations (Nm 24:8; Dt 33:17). Unicorn is an unfortunate translation (following the Septuagint) because the animal had two horns, not one. See Animals (Wild Ox).
Unicorn
From Tyndale Bible Dictionary, adapted by Mission Mutual. CC BY-SA 4.0.