Something can always kick your ass.
This was released back in 1987, and I was still in high school at the time. Back in the day the special effects were very good, these days they may be a little dated. The story and the action scenes have stood up quite well to the passage of time.
An extremely short overview of the story line is that we have a team of special forces personnel that are sent into the South American jungle. Supposedly on a rescue mission to find any survivors from a crashed helicopter.
The team is used to being able to finish any mission with relative ease, they are some of the toughest guys around after all. It quickly turns out that the actual mission was something else altogether, this however isn't their immediate problem.
There is something else in the jungle that likes a good hunt, and they have just been selected as the prey. The predator chasing them seems to have camouflage and weapons far beyond anything they have. According to the locals they are being hunted by something not from Earth that cannot be stopped. It can only be avoided which is too late for them to do, they have been selected.