In 1977, Pete, a five-year-old kid, is on a street trip with his folks when their auto flips off the street attempting to evade a deer. Pete's folks are executed, however Pete survives and is pursued into the timberland by a pack of wolves, just to be protected by a mythical serpent with green hide, yellow eyes, and immense wings. Pete names the monster 'Elliot' after his most loved book about a puppy of a similar name with its family, and takes to him as a father figure.

After six years, Pete, now 11, spots a logger team hacking down trees close to his home. Natalie, the little girl of the site foreman, spots and pursues him. At the point when Natalie incidentally tumbles from a tree, her shouts draw in her dad, Jack, and his better half, stop officer Grace Meacham. Pete tries to flee, however Gavin, Jack's sibling, inadvertently thumps him oblivious. Subsequent to understanding that Pete has vanished, Elliot staggers around searching for him and winds up thumping over a tree close to the wood camp, driving Gavin to arrange a chasing gathering to discover him. In the interim, Pete awakens to end up in a neighborhood healing center, which he escapes with an end goal to come back to the timberland. Prior to the police can get him, Grace discovers Pete and persuades him to come live with her by promising to take him to the woodland the following day.

Gavin and his men find Pete and Elliot's treehouse, however when they attempt to hunt it, Elliot uncovers himself and alarms them away. He then tails them back to town with an end goal to discover Pete. When he does, be that as it may, and discovers Pete settling in with Grace's family, he clears out. In the wake of getting a drawing of Elliot from Pete, Grace takes it to her dad, who cases to have found an indistinguishable mythical serpent from a young fellow. He encourages her to put stock in Pete, and to discover Elliot.

The following day, Pete, Grace, Natalie, and Mr. Meacham go to the timberland to meet Elliot. A gathering of seekers drove by Gavin amaze Elliot and sedate him, securing him up Jack's stockroom. Prior to the specialists can examine Elliot, Pete and Natalie free him from his chains and escape on a timber truck with Mr. Meacham.

Irritated, Gavin sets up a detour at the extension to stop them. A fizzled endeavor by a still lethargic Elliot to fly harms the truck's brakes, making the truck push through the blockade and grind to a halt at the opposite side. Confounded and scared, Elliot roosts himself on the extension and begins breathing flame at the police. The scaffold starts to crumple under the exceptional warmth, making Grace and Jack's truck fail to work out. Gavin then disregards following Elliot, and tries to spare them before they tumble to their passings. Elliot tries to prop them up, yet the scaffold abruptly gives way and they all fall into the gorge. Finally, Elliot rises with Grace and Jack on his back. With a military helicopter drawing nearer, Pete chooses to escape with Elliot back to the forested areas.

Pete begs Elliot to remain with him so he can shield him from his assailants. In any case, Elliot infers that the length of they remain nearby together, Pete will dependably be in peril. He indicates out Pete's book attempt and persuade him to backpedal to Grace and Jack. Pete is hesitant at to begin with, however trusts Elliott's judgment. After a weepy embrace, Elliot comes back to the mountains, while Pete goes to live with Grace and Jack as his new family.

In the years that take after, Grace and Jack wed and receive Pete as their child, Gavin proceeds onward from the experience, and Elliot gradually blurs from the town's memory. In any case, Pete and his family discover him while in the midst of a furlough, having found that Elliot has at long last rejoined with his kindred mythical beasts.