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 mythological action movie based on a graphic novel. Dwayne Johnson was born to play Hercules, the world's strongest and bravest hero, and the rest of the cast is also very good. Most of the action takes place after Hercules has performed his legendary 12 labors and travels around with five other people, working as a group of mercenaries - an Amazon warrior in a leather mini skirt, a mute who is part wild animal, a Spartan soldier, a young man who tells stories about Hercules to attract business, and an old man who can see the future. Hercules only wants to keep working as a sword for hire until he makes enough money to retire somewhere nice and give up the hero business. He only needs one more big job. So basically this is another one of those "one last mission" movies. He is hired by the King of Thrace and his daughter to defeat a tyrannical warlord. Or so he thinks....
Unfortunately, I'm not here to talk about any of the other fun stuff, only the snake scene which is very brief and happens at the very beginning when we are introduced to the character of Hercules. (Hercules is the Roman name for the Greek hero Heracles, but this movie uses the Greek names for the other characters.) According to the myths, which this movie follows, Hercules is the illegitimate son of Zeus, the king of the gods, and a mortal woman named Alcmene. Zeus' wife the goddess Hera is furious that her husband fathered a child with another woman so she sends serpents to kill baby Hercules in his crib. The snakes fail and he kills them instead. This snake-killing is typically mentioned in every story of Hercules since it shows that even as a baby he was strong and fearless.
The myths don't say how Hera sent the snakes or how many she sent, but here we see two of them break through the marble and emerge out of the eyes of a statue of Hera. We see the snakes drop from the statue and crawl over to Hercules, as Alcmene watches, until they are just about to attack him. We don't see him kill the snakes, we only see the aftermath of the fight when he holds a dead snake in each hand.
I've seen statues and paintings that show baby Hercules fighting the snakes, but I don't remember ever seeing this part of the story in a movie. Someone must have shown it, so I probably have not seen enough Hercules movies.
The snakes are made with computer animation, but the effect is realistic enough for how briefly they're on screen.