Canned meat is never a good option. If you cannot get fresh meat, frozen is better.
rainbows are rare? you can turn on a hose and see one?
According to Metalocolypse, they are large demonic creatures that sleep at the bottoms of Lakes, only able to be awakened or put back to sleep with music. The episode notes that it kills Unicorns, but never states why.
That's not the same and you know it.