1 Darwin’s frog. In the forest streams of Chile and Argentina lives a fairly unpresuming looking frog. Physically, it resembles a dead leaf, a trait that helps it hide away from predators. But pretty neat camouflage is not enough to make this list: what really sets Darwin’s frog apart is how it goes about its business of making new frog babies.
Things start out pretty normally, with the female laying some eggs and the male guarding them until they hatch. Now we’re about to get weird. Instead of letting the wee baby tadpoles make their own way in life, the male swallows them and carries his kids in his vocal pouch. The tadpoles develop, feeding off the yolk from their eggs, and after they reach about ½ an inch in size, they just hop out of their good ol’ dad’s mouth.
2 Platypus. I cannot make a list like this without my favorite weirdo animal. For starters, the platypus resembles what would happen if an animal was thrown together using spare parts. For seconders, this otter-duck-beaver-looking weirdo is a monotreme, so it is one of the few mammals that lays eggs instead of giving birth to live young. If that wasn’t enough, the platypus has mammary glands, but no teats, so it just exudes milk from its pores, which its young laps up. Oh, and both male and female platypus have ankle spurs, but males match this spur with a venom so powerful it can paralyze a human. There are only a small handful of venomous animals, and most of those are shrews who release the venom through their teeth when biting prey, which is significantly more normal (but, since they’re mammals and not, say, snakes, still sort of weird).
3 Glass sponges. Sponges might not look like much, but as members of the phylum Porifera, they are definitely animals. They don’t have much in the way of a digestive, nervous, or circulatory system, but hey, that just makes them all the weirder. Many sponges have basically endoskeletons made from calcium carbonate. Many marine organisms make shells or other hard body parts from calcium carbonate, so that seems fairly normal. However, a small group of sponges use glass instead. These sponges, called hexactinellid sponges, pull silicic acid from the ocean water, convert that to silica, and build these elaborate glass skeletons. The most well known example is called Venus’ Flower Basket, which just sounds lovely and almost hides the fact that these bizarre creatures are basically using biology to make glass.
What’s your favorite weirdo animal? Have any to add to this list?