4. Pygmy Sperm Whale

And just when you thought size is everything, meet the pygmy sperm whale. Although females may reach almost four meters in length and males three meters long, the pygmy sperm whale can be considered small when placed alongside other cetaceans. When threatened, the pygmy sperm whale shoots out a reddish brown liquid out of its anus to confuse predators as it makes its escape. This behavior, more akin to those of cephalopods like squids and octopuses, is highly irregular in mammals and has baffled scientists for years.