Many translations have wild ox and unicorn. Wild ox doesn't make sense to me in the place of Job because it seems to be referring to a domesticated animal.

Here are some other translations:

buffalo (Darby and MLB)
forest-ox (Leeser)
ox of the mountains (BBE)
reem (YLT, this is a transliteration)
rhinoceros (DRC, RCC translation from Vulgate)
unicorn 'ox' (UKJV, exactly how it appears...)

Oh, and here's an evolution of the spelling of unicorn:

1395 Wycliffe: vyncorn
1534 Tyndale: vnycorne
1535 Coverdale: vnicorne
1568 Bishop: vnicorne
1587 Geneva: vnicorne
1611 King James: unicorne
1769 King James: unicorn

__________________
Jake; Hold to Original WCF, member of SBC; Greater Atlanta, Georgia Area

The cross does not give us a minor shift or two with regard to a few of our ethical and moral and religious values; the cross radically disrupts the very center and citadel of your life from self to Christ. —Albert N. Martin