Everything But the Kitchen Sink
There is a famous saying: "God has a sense of humor. Just look at the platypus." True to its reputation, the platypus seems like an evolutionary joke, and was thought to be a hoax for years before its existence was confirmed. It lays eggs and has a bill like a duck (despite being a mammal), electrolocates like a dolphin, has the tail of a beaver, warms itself with fur thicker than that of polar bears, and sports venomous spurs on top of everything else. It is truly a natural oddity, and a testament to the diversity of life on Earth.