Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This movie is about smuggling cocaine into the U.S. in small airplanes in the 1970s and 1980s and smuggling weapons out of the U.S. to the Contra rebels in Nicaragua. There have been allegations that the C.I.A. was involved in cocaine trafficking and starting the crack epidemic in the U.S. but according to this story, they funded the smugglers to smuggle weapons to Nicaragua and later to smuggle rebels into the U.S. for training, while ignoring the fact that the smugglers returned from Central and South America with planes full of cocaine and cash.
The subject of this movie, Barry Seal (Tom Cruise) was a commercial airline pilot who got tired of his job and was recruited by the C.I.A. to fly weapons to Central America. He decided on his own to get involved with a budding Columbian drug cartel and started flying large shipments of cocaine to the U.S. on his return trips. After his involvement with the C.I.A. was ramped up to include the military and White House employees, Seal was eventually arrested and convicted, but he bargained his way out by becoming an informant against the cartels who then assasinated him.) He became so successful that he had to get more planes and hire four more pilots.
The snake scene is extremely brief.
We see a shot of Seal's four new pilots walking on the runway. One of them has a boa constrictor around his neck that he takes with him in his plane. (Maybe he picked it up in Central or South America, where the boas come from.) The movie is loosely based on Seal's life, but I can't find out if one of Seal's pilots really did fly with a snake. If he did, maybe he's the pilot who inspired the pilot in the first Indiana Jones movie who also flew a small plane with his pet Boa Constrictor.