Today I learned: Mimic Octupus

The best camouflage in the world belongs to the mimic octopus. It can imitate over 15 other species through a characteristic that's incredibly rare in the animal kingdom called active mimicry. Most species rely on passive mimicry, which means that they have no choice in what they resemble—the disguise has just been handed to them through millions of years of evolution. The mimic octopus doesn’t just camouflage itself—it does dead-on impersonations. And lest one think that it’s easy to fool fish because they’re stupid, the mimic octopus is so good at disguising itself that humanity didn’t even officially recognize it as an existing species until 1998.