Michael Shermer, who appears in the video, asks Christians to explain why there are unicorns in the Bible. (H/T Letitia) The Bible certainly mentions the word unicorn. But does it refer to the mythical horse-like creature, like Shermer seems to think?
Once you go back to the original language, it turns out that the unicorn that is mentioned is really a rhinoceros.
You can read a debate between Greg Koukl and Michael Shermer here. This debate was moderated by radio show host Hugh Hewitt, and presumably transcribed by his much-maligned producer Duane Patterson. Hewitt also moderated the famous debate at Biola University, featuring William Lane Craig and Christopher Hitchens.