Image removed because the Narwal image police came after me.
The New York Times had a really interesting article about the narwhal whale last week. For those too lazy to read the whole thing, there are these whales with long straight tusks that nobody had a clue what they were used for. And the new discovery part is that it is a type of sensory organ that can do neat stuff like sense the salinity of the ocean to determine whether it might be prone to freezing on them.
Props to Elf for including a narwhal, with a speaking part no less. (Audio clip from the movie here .WAV)
They are my new favorite whale.