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 murder mystery based on an Agatha Christie novel about a group of high society people, the kind who wear gowns and tuxedos to dinner, on a sightseeing boat on the Nile River. A woman is murdered, then two others, and everybody is suspected until the famous Belgian detective Hercule Poirot, who just happens to be on board, solves the mystery. Much of the film is filmed on location in Egypt with some great scenery and the costumes won an Oscar. It's also great fun to watch the cast full of Oscar-winning actors chew up the scenery, but the movie drags a little. Fortunately, there is a nice long scene with a Cobra that is used as a weapon to wake us up.
The Snake Scene
Peter Ustinov is detective Hercule Poirot, who is famous for his crime solving as well as for his "immense black moustaches," according to the book. David Niven is Colonel Race, an ex-military man. They return separately to their adjoining cabins on the boat to freshen up before lunch. For Poirot, that means waxing his stupendous soup strainer. As he waxes his luxurious lady tickler we see a large cobra on the floor at his feet. When Poirot sees the snake, he freezes and stops waxing his copious cookie duster. (Alright, alright, I'll stop describing his voluminous lip foliage, but I've got a lot more...) Slowly Poirot moves his hand towards the wall separating his bathroom from Colonel Races' bathroom and taps an SOS. Colonel Race hears the distress call it and runs to grab his cane, which has a sword in it, because who doesn't travel with a cane with a sword in it? Race runs over to Poirot's cabin and slowly creeps up on the cobra, then stabs it in the throat with the sword. We see an extended shot of him twisting the sword around, just to make sure the snake is dead. Then we see a shot of the snake falling to the floor. (The dead snake looks different from the live one, but I doubt anybody noticed but me.) Then Poirot returns to waxing his monumental mouth brow.
Poirot says to Race: "I must thank you for a most timely deliverance."
Race: "It's my pleasure. I heard your SOS. Do you think it was put there deliberately?"
Poirot: "Of course it was. But it will take more than a serpent to interrupt the investigation of Hercule Poirot."
The manager of the boat enters the room and Poirot asks him to remove the cobra. He says he has never seen such a reptile in a first class cabin, then walks to the railing of the ship and throws the dead snake overboard.
Later, after Poirot exposes the murderer, we learn that the snake was brought on the ship originally to kill someone else, but the plan was abandoned and the snake was then used to try to bump off Poirot. It makes sense that the killer would want to kill Poirot, who could expose him, but using a snake as a murder weapon is never a good idea. There is no snake in the novel this movie was based on, so the killer cobra and its attempt on Poirot's life are additions to the original plot.
The snake we see in the bathroom is a live cobra, but when it falls dead to the floor we see a fake snake. When the steward carries it and throws it overboard, it's probably also a fake. The live snake was certainly filmed somewhere off the set away from the actors to keep them out of danger, then the fake snake was used on the set with them. That's typical. I don't mind seeing realistic fake snakes like this one stand in for the live snake we just saw after it is supposed to be killed, because it means that they did not killl a live snake just to use it in the movie. Compare this scene with the snake scene in the 2022 film version of the novel, in which the snake is computer-animated. I think I'd rather see a rubber snake.