The Giant Eel is a minor villain in the 2005 Peter Hyams film A Sound of Thunder. He is a serpent-like creature which appeared in the Present after the death of a butterfly in the Cretaceous changed the course of time.
When Travis Ryer, Sonia Rand and Jenny Krase decide to go to a nearby university in order to use the particle accelerator located there as a time portal, they are forced to go in a flooded tunnel in order to follow the subway tracks to the university. However, the Giant Eel sees them and tracks them. Shortly after, the group has to get inside a train car, but at the same time the ceiling of the tunnel gives way, causing a flood. Taking advantage of the situation, the Eel manages to burst through a window and devours Jenny, which floods the inside of the train. Then, while Travis and Sonia are underwater, he bursts another window to penetrate inside the train and attack the two. Sonia manages to escape and Travis tries to shoot at him with his gun, but it doesn't work. The Eel attacks him, but he seizes a knife and injures the creature, which seemingly flees. However, before Travis could escape from the train, the Eel grabs him with his tail and attempts to devour him, but the train's ceiling caves in and crush the creature, killing him. Sonia then helps Travis to rise to the surface of the water, and here they see the dead body of the Eel floating.
- In Ray Bradbury's short story which inspired the movie, the Giant Eel did not appear.