Which of these creatures is mentioned in the King James Bible?

That’s a stretch

Butterfly is mentioned, one horn could be a Rhinoceros, not a unicorn.

This is one of those big stretches. One horned, great(est) horned, biggest Horned, all are acceptable interpretations, which are more likely to describe an Oryx, a Giant Buffalo, or a Rhinoceros, along with the Unicorn; which falls much lower on the list.

I agree, it's a stretch. A "horned animal" is any animal with horns. Eg. a bull is a horned animal.

one of many pieces of evidence that the bible is nothing but mythology

Player #14737963, rhinos have 2 horns