Pliny the elder:

"...An exceedingly wild beast called the Monoceros, which has a stag's head, elephant's feet, and a boar's tail, the rest of its body being like that of a horse. It makes a deep lowing noise, and one black horn two cubits long projects from the middle of its forehead. This animal, they say, cannot be taken alive."

Solinus
"the unicorn is a monster, a cruel animal with a horrible bellow, a horse's body, elephant's feet, a swine's tail, a stag's head and a sharp, piercing horn in the middle of his forehead; he cannot be caught alive."

God asks Job, "Will the unicorn be willing to serve thee, or abide by thy crib? Canst thou bind the unicorn with his band in the furrow? or will he harrow the valleys after thee?" (Job 39:9-10).

Numbers 23:22 God brought them out of Egypt; he hath as it were the strength of an unicorn.

Numbers 24:8 God brought him forth out of Egypt; he hath as it were the strength of an unicorn: he shall eat up the nations his enemies, and shall break their bones, and pierce them through with his arrows

Deuteronomy 33:17 His glory is like the firstling of his bullock, and his horns are like the horns of unicorns: with them he shall push the people together to the ends of the earth: and they are the ten thousands of Ephraim, and they are the thousands of Manasseh.

Job 39:10 will he harrow the valleys after thee? 11 Wilt thou trust him, because his strength is great? or wilt thou leave thy labour to him? 12 Wilt thou believe him, that he will bring home thy seed, and gather it into thy barn?

Psalms 22:21 Save me from the lion's mouth: for thou hast heard me from the horns of the unicorns.

Psalms 29:6 He maketh them also to skip like a calf; Lebanon and Sirion like a young unicorn.

Psalms 92:10 But my horn shalt thou exalt like the horn of an unicorn: I shall be anointed with fresh oil.

Isaiah 34:7 And the unicorns shall come down with them, and the bullocks with the bulls; and their land shall be soaked with blood, and their dust made fat with fatness.