The really logical answer (at least that's what my brain tells me it is) would be "if I was an animal, then I probably would have come into being the way most animals do: by having two other animals of my species decide it was breeding time".
There's another technicality I should point out: you could argue that in terms of biological classification, I'm already an animal, in the sense that humans as a species are much more animal than they are plant or fungus or bacterium, i.e. in the sense that we've got bones and muscles and nerves and bloods and vital organs, we lack roots and leaves, and so on.
However, I suspect the question was meant to imply a transition from being human to being an animal. So, if I had achieved this feat, how would I have done it?
Having never done it, I don't have a definitive answer. But there are all sorts of exciting - read: worrying - hypotheses, which I shall list in order of decreasing probability (and, for the most part, of decreasing appeal):
- Maybe a mad scientist kidnapped me and transferred my consciousness into a different body?
- Maybe I was surreptitiously fed a gene graft formula by an unscrupulous aide?
- Maybe I changed species during a freak teleportation accident?
- Maybe I got bitten by a radioactive mutant thing and started expressing its genes instead of mine?
- Maybe my life is part of a really weird webcomic, and I changed by cartoon logic?
- Maybe I got abracadabra-ed by a senile old fairy godmother who was aiming for somebody else?
- Maybe I set my heart on changing species, wished really really hard, and got what I wanted?
- Maybe I died and it turned out the Hindus were right?
Now, if you'd asked what animal I would have been, that'd have made for an entirely different blog post. But you didn't.
- Species, at last check: Homo sapiens
- Twenty Questions status: 8 down, 12 to go
- Days until Root Hill: 16
- Latest book read: ...keep assuming, etc...
- Latest film/TV watched: The Bourne Ultimatum
- Latest music listened to: still How to Train Your Dragon OST (I think)
- Latest edible item eaten: beef burger
- Predominant colour of clothes: back to blue
- Programs and web pages currently running: Microsoft Office Outlook 2007, Firefox (tabs: Blogspot Dashboard; Blogspot Create Post; MatNav 6.1); Skype
- Webcomics posted today: Cylinder and Miserable #1328 and 1329; Fort Paradox #69 (going away for the weekend, so I posted them early)
- The Colclough