Rodney was minding his own business on a windowsill next to a suspicious experimental syrum, when a sudden shoulder bump from a careless scientist knocked the whole thing into him!
In a matter of moments he was big enough his tarsi alone were the size of skyscrapers, and it certainly didn’t take him too long to get into the role…
He’s a big fan of mothra, imagine turning into your idol + some in an instant. I would do the same thing if I were him.