I bring some funny stuff back on planes but I have never brought snakes. Thing is, if you did it would go in the cargo area, it's probably about -20degrees in that thing. If you really had to do it, and it wasn't that long of a flight, you could get some type of warmer that YOU feel is sufficient for the entire duration + of the trip. It may be picked up on the screen that something warm or living may be in the suitcase.

Just strap it to your inner thigh man.