Well, at least I know where a rhinoceros got its name, tsuwm. :) Except a rhino's nose isn't really a nose, and it isn't really a horn either. It's hair. [It's not exactly hair, either. It's "keratin".]

Rhinoceros horns are derived from the dermis of the skin. They are solid and are composed of an aggregation of thousands of incredibly strong, tightly packed, compressed keratin fibres. The horns are perched on a roughened bump on the skin, over the nasal bone, and do not have a bony core down the middle.

The horn may unravel in places, so that it resembles a growth of hair. If it tears, only a lightly bleeding area remains on the nose and a new nose begins to grow soon. Young animals may replace the horn completely.

http://experts.about.com/q/705/3675908.htm