I'm thinking and thinking and I don't think I've ever heard anybody tell me they don't have personalities...
Even my snakephobic family thinks they're just plain evil - yeah, the devil personality. I mean, they're all Catholics - they think the snake gave Eve the apple that caused Adam and Eve to get kicked out of Eden. Definitely lots of personality there.
My bps have different personalities too. But, my favorite snake personality-wise is our hognose. He is a trip! Hissing like a cobra, rattling like a rattlesnake, striking with his snout... it is hilarious!