A group of soldiers have to investigate a certain group, while their superiors, the Government have a secret of their own.
- Olsen McKelly (Ryan Kelley) - the film's main protagonist, joined the military of his late mentor, Daniel Ferris (Chris Evans), he married Veronica McKelly (Melissa Benoist) and raised a daughter named, Brie (McKenna Grace), he gets the military led by Galen Gordon (Joel Kinnaman) into the mission to Project Jackson, to find intel on The 5 Deadly Venoms, which near the end, leads them to discover that his mentor was behind it, in the end, reunites with his family.
- Mortimer Paxton (Nick Palatas) - the film's deuteragonist, Olsen's (Ryan Kelley) best friend, also a member of the military, has a girlfriend, Juliana (Shailene Woodley), who is a nurse, whose relationship is one of the main focuses of the film, in the end, he marries Juliana.
- Lt. Galen Gordon (Joel Kinnaman) - the film's tritagonist, the leader of the group including Olsen (Ryan Kelley), Mortimer (Nick Palatas), Nicholas (Scott Eastwood) and Vance (Michael B. Jordan) into Project Jackson to find intel on 5 Deadly Venoms, he is very strict, always given the nickname, "Lt. Harda**", but he has a hidden heart of gold, when it comes to his fiancé, Theresa (Maggie Grace), in the end, gives up his life to stop a horde of Venom Beasts.
- Veronica McKelly(Melissa Benoist) - Olsen's (Ryan Kelley) loving and supporting wife, and mother of Brie (McKenna Grace), in the end, greets her husband.
- Brie McKelly (McKenna Grace) - Olsen and Veronica's (Ryan Kelley and Melissa Benoist) daughter, in the end, is seen dating a boy.
- Juliana Grace (Shailene Woodley) - Mortimer's (Nick Palatas) girlfriend and a nurse, who worries for him, in the end, she marries him.
- Theresa Gooding (Maggie Grace) - Galen's (Joel Kinnaman) fiancé, whose the reason he has a hidden heart of gold, in the end, mourned his head.
- Nicholas Orion (Scott Eastwood) - a member of Galen's (Joel Kinnaman) team to Project Jackson, in the end, he dies saving Vance from the Scorpion.
- Vance Thompson (Michael B. Jordan) - a member of Galen's (Joel Kinnaman) team to Project Jackson, in the end, Returns home with the apprehended Col. Black.
- Colonel Even Black (Woody Harrelson) - Galen's (Joel Kinnaman) superior, who partners him and his team with Captain Jasper Cromwell (Josh Brolin) and his team, in the end, he was exposed a traiter in league with Ferris and was apprehended by Vance.
- The Government: first appeared as allies to the military on Operation Jackson, though it was revealed near the end, They were trying to foil The 5 Deadly Venom's scheme.
- Jasper Cromwell (Josh Brolin) - the leader of the Government squad, who appears as an ally at first to the military squad, though it was revealed near the end, He was undercover from the President to arrest any who help the 5 deadly venoms, in the end, he was killed by Cobra.
- Su-Yin (Ming-Na Wen) - Jasper's (Josh Brolin) right hand woman, and loyal friend, near the end, she was revealed she was Cobra and kills Jasper, in the end, She was arrested by Vance.
- Malcolm Troy (Boyd Holbrook) - a member of Jasper's (Josh Brolin) group from the government, who was revealed as the scientist who created the Venom beasts for Ferris, in the end, he was killed by the Toads.
- Dante Walsh (Mahershala Ali) - a member of Jasper's (Josh Brolin) group from the government, who was revealed as an undercover from the UN to stop Ferris's mad dream, in the end, He saves the people who are experimented on.
- Broyd Gump (Kirk Acevedo) - a member of Jasper's (Josh Brolin) group from the government, who was revealed as a Spy for the UN, in the end, joins the fight against the Venom Beasts.
- President Liem Porter (Harrison Ford) - the President of the United States, in the end, awards McKelly for his rescue.
- Viper Jaw (Dijimin Homonsou) - a terrorist leader, he appeared to be the main antagonist at first, until near the end, he was revealed to be a puppet and pawn by Daniel Ferris to help create the Venom beasts, in the end, He turns himself over to the police
- Scorpion (David Sobolov) - Viper Jaw's right-hand man, who was working with him on the 5 deadly venoms, he was killed in the beginning.
- Daniel Ferris (Chris Evans) - McKelly's (Ryan Kelley) mentor who led him to the military, he sacrificed himself to save him from a mine, costing him his life, but revealed he faked his death to cover that he is the actual leader of the Five Deadly venoms as Komodo, in the end was killed by Galen who feeds the beasts him.
- This film is rated PG-13 for ???