Quote Originally Posted by patm1313 View Post
No, freezing is very painful for all animals, except for some very young mammals. You could, however, put it in a container with air holes in the fridge, which will render the snake unconscious. The you may put it in the freezer to kill it painlessly.

Or, you could flatten the head. This is OK if done instantaneously. The body may still move, but the snake isn't making it move, it's just normal post-mortem movement, which happens in many animals.
I am pretty sure most users on this site euthanize their snakes using the freezer method. I am not sure the reason why, but it is very quick. Snakes are exothermic, they will die very fast in a freezer because they can maintain no heat whatsoever. The colder they get, the slower their body functions get, until they completely stop. I am pretty sure this is a relatively painless process.