Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
Only hardcore giant snake movie fans should bother to watch this absurd mess. It's a made-for-TV sort-of sequel to Python (2000), and it's followed by two more sort-of sequels: Python 2 (2002), and Boa vs. Python (2004).
In what must be the future, 35 nations have constructed a secret international high-security prison for the worst of the worst prisoners called New Alcatraz, hidden deep under the ice 20 kilometers north of the south pole where it is 67 degrees below zero in the winter. For some reason, they drilled a huge hole 9,000 feet under the ice, which opened up a large hollow rock full of nitrogen in which a 20 million year old gigantic snake has been hibernating. (This has to be one of the worst premises for a monster snake appearance I've ever seen.) The hole lets the snake crawl up into the prison. It's hungry, so it starts to eat everybody it finds, mostly prison guards. They fly in some eggheads who study ancient reptiles because they're the closest to experts they can find. They do nothing except babble about snakes being attracted to heat. But even sub-zero temperatures and an army of men in snow camo can't stop the snake. Eventually they have to release and arm the prisoners, who are well-suited to the task because they're all dangerous killers, to try to kill the snake. The finale where somehow the snake sneaks onto an airplane with the few remaining survivors who manage to throw it out of the plane, is totally insane, and that's exactly what we want to see in a movie like this, but it was too little, too late.
The CGI monster snake is so dark and blurry we can barely see it, but it does look like it could have been modeled after a Boa Constrictor. It constantly growls and screams. It has huge fangs and a prehensile tail that has a barb on the end so it can either wrap around someone or just skewer them with the tail. Like most movie monster snakes this one is continually chasing and killing people, but unlike most of them, at least this big boa is killing for a reason. It hasn't eaten in 20 million years, so it's a bit peckish.