A monster or parasite that grows inside a human body.

During its return to the earth, commercial spaceship Nostromo intercepts a distress signal from a distant planet. When a three-member team of the crew discovers a chamber containing thousands of eggs on the planet, a creature inside one of the eggs attacks an explorer. The entire crew is unaware of the impending nightmare set to descend upon them when the alien parasite planted inside its unfortunate host is birthed.

Ripley, the sole survivor of the Nostromo's deadly encounter with the monstrous Alien, returns to Earth after drifting through space in hypersleep for 57 years. Although her story is initially met with skepticism, she agrees to accompany a team of Colonial Marines back to LV-426.

In the winter of 1982, a twelve-man research team at a remote Antarctic research station discovers an alien buried in the snow for over 100,000 years. Soon unfrozen, the form-changing creature wreaks havoc, creates terror... and becomes one of them.

Scientists and US Air Force officials fend off a blood-thirsty alien organism while investigating at a remote arctic outpost.

A small town is taken over by an alien plague, turning residents into zombies and all forms of mutant monsters.

While searching for a small fortune of embezzled money, an ex-con, a small-time bandleader, his doting wife and a kooky drifter find themselves being followed. Their chase takes them to trailer camps, bingo halls, laundromats and ultimately, a showdown with a group of unconventional bad guys.

A young woman contracts what she believes to be an STD—but it ends up being a far worse disease.

Picking up directly where the previous film left off, the story follows Riley, one of the last people to come in contact with Samantha, as he scrambles to track down those responsible for the outbreak before the highly contagious disease not only consumes his body, but the world as we know it.

When Seth Brundle makes a huge scientific and technological breakthrough in teleportation, he decides to test it on himself. Unbeknownst to him, a common housefly manages to get inside the device and the two become one.

Test space rockets exploding at liftoff and increased reporting of UFO sightings culminate in a direct attempt by alien survivors of a dead, extra-galactic civilization to invade Earth from impervious flying saucers, using ray-weapons of mass destruction.