PLATYPUS

So here's how I see it. After the whole Noah's Ark thing, the animals got busy. I imagine that the platypus was not alive until after the flood. Why? Well, repopulating an entire planet can be stressful, but at the same time nobody would argue assuming that their mate was attractive. Ahem. Anyway, I'm pretty sure one night, a duck wandered into the wrong tent while drunk, and then nine months later the platypus comes along.

That's my theory and I'm sticking to it. Don't get me started on my theory on giraffes.