Well, now I have proof. My mum has been going through some old files, and she found an excel spreadsheet I made when I had just turned 13. It's an inventory of all of my stuffed toys (I had quite a lot).
Here is a snapshot of it (with spelling mistakes preserved):
And yes, I had a Leopard named Cheetah.
I'm actually REALLY glad I made this at that time, because I wouldn't remember the dates these days. So, I'm quite proud of myself for recording this seemingly useless information before I forgot it. :P