Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a action adventure film set in the past when Vikings travelled the world, based on a Michael Crichton novel. Antonio Banderas is Ahmed Ibn Fahdlan, an Arab sent far from home on a diplomatic mission as punishment for messing around with a powerful man's wife. He stops at a Viking port as the Vikings learn that a village in their homeland is under attack by mysterious horned demons who eat their enemies known as the Wendols. An old Viking woman oracle advises them to send 13 warriors, with one of them being a foreigner, so they force Ahmed to go with them. After several battles with the Wendols, who far outnumber them, they realize that the Wendols are just men who wear bearskins and horns and ride horses. Facing overwhelming odds, the Vikings follow the advice of an oracle who tells them in order to defeat the Wendols they must kill their leader and their their spiritual mother.
The remaining Viking warriors sneak into the enemy camp and descend into an enormous underground cave filled with the bones and skulls. Going deeper into the cave, past severed heads hanging from the ceiling which include some of their dead comrades, the Viking leader Buliwyf finds the Wendoll mother. She wears an elaborate headdress made of human teeth and has a large pointed bone that looks like a large fang attached to her fingers. As she fights Buliwyf, she dips her finger fang into the top part of a crushed human skull used as a bowl that is full of snake venom, then she sticks Buliwyf with the fang just before he cuts off her head. Buliwyf slowly becomes ill and dies the next day from the venom.
The snake we see is a tangerine phase Honduran Milk Snake, a non-venomous snake from Central America. Milk Snakes are often used in movies to portray deadly snakes because of their red coloring, but they are harmless and a very popular pet snake.