Anybody seen or have a pet snake in the truck?

No. There is no good place for it. In fact if you entered some inspections related to agricultural etc you might be refused. Snakes generally have parasites inside them. It cannot keep warm most of the time there is no place to do it. Even if you put a tank in there with a heat lamp there is a risk a bad bridge will smash the glass. Etc etc etc.

Im sure it's been done, but it's very uncommon. Some snakes when they get big enough to kill a child or overpower a adult becomes a problem.

 

I knew a driver would take his snakes with him occasionally.
He would feed them before he went on a trip so they wouldn't get hungry.

He enjoyed "show and tell" at the truck stop.