Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is an adventure story about a love triangle between a hunter a trapper and the hunter's girlfriend. They all go to Malaysia to capture tigers for a German zoo along with "The Enchantress" a big cat that is half leopard/half tiger. Robert Mitchum is Harry, a trapper and Jack Hawkins is Otto, a hunter, whose companion is Anna (Elsa Martinelli), a human "enchantress" who both men compete for. The love triangle only intensifies the fact that trappers and hunters don't get along. Martinelli starred in the Howard Hawks/John Wayne movie Hatari the year before this was made, and the Rampage producers probably used her to try to cash in on its success.
Rampage is a good example of how a movie prepares the audience for a snake appearance:
In the USA, when planning their trip, Otto tells Harry they are going to the Pahang, the Malay Rainforest where "Tropical flowers grow in the topmost branches, and cobras in the lower ones."
(Now we're ready for some cobras in trees.)
Once they get to Malaysia we see Harry holding a big handgun that he says he is carrying for the cobras that decorate the branches.
(Now we're ready to see Harry shoot a snake in a tree.)
Next we see one of the vehicles they use to travel through the forest pass by a large snake wrapped around a tree. (It looks like a fake python, not a real snake.)
(Now we've seen that there are snakes in trees.)
Shortly after that we see the group walking through a forest directly under a snake hanging on a branch. Harry draws his handgun, shoots it, and kills the snake.
All this was set up and executed so Harry will look like a hero for saving Anna, but Otto tells him that there was no need to shoot the snake (which he calls a Krait, not a cobra, but a different kind of venomous snake). In a last gasp attempt to block Harry from getting Anna, Otto tells Harry that he and Anna saw the Krait but it was too high to strike. He tells Harry that he's not a hero, but Anna seems to disagree and falls for Harry.
The second snake (Krait) is also a fake, but they get props for giving it a banded pattern, like you'd see on a real Krait.