Alien (Without Warning)

The Alien is the main antagonist of a 1980 horror-science fiction movie Without Warning. He is played by Kevin Peter Hall, who later played the Predator

Role
Before the film starts, it came to Earth for a sport and collect several trophies and uses a shack as it's main camp and keeps its "trophies". At the beginning, the alien killed two hunters with it's jellyfish discs, which penetrates their skin with needle-tipped tentacles.

Later, it killed a scoutmaster, 2 teenagers on a hiking trip and tried to kill two of their friends and followed them.

Greg and Sandy, one of the two teenagers, sleep at a house, until the alien killed Greg and got shot by Joe Taylor, a truck stop owner.

Joe placed some dynamite at the shack, where the alien keeps the bodies, but got interrupted by Fred "Sarge" Dobbs, a mentally ill veteran, Sarge saw the alien, talking crazy and pointing his gun at it and the alien, in turn, threw it's discs at Sarge's chest, killing him.

Joe fired one round at the alien's arm, and threw a disc at his chest, but Joe cut the disc out and it threw another one on his back. Joe tells Sandy to start the dynamite when he lures the alien to the shack. Sandy tried to push the plunger but the wire wasn't attached to it, Sandy is able to fix it and while Joe, almost succumbing to his wounds, grabs the alien by the leg till Sandy was able to blow up the shack.