Do we originate from a monkey and pig experimenting with interspecies sex?
First I thought this was a silly idea; a thought experiment. Then I read more and realised that it mindboggingly makes sense! Religious people might not like it. Although, another way to look at it is that eating pork is kind of like cannibalism, so perhaps the muslims were right all along!
And just like humans might come from chimp-pig hybrids, platypii are apparently best explained by hybridisation between a bird and an early mammal. As, of course, aborigines knew since a long time ago.