Villain(s)  Martian creature

Actor(s):  Marshall Thompson, Shawn Smith, Kim Spalding, Dabbs Greer

Brief Description  It! The Terror from Beyond Space is a 1958 black-and-white science fiction horror film directed by Edward L. Cahn and written by Jerome Bixby. It follows a rescue spaceship sent to Mars to find the lone survivor of a doomed prior expedition, only for a hostile, indestructible alien to stow away and hunt the crew during their flight back to Earth.

Plot:
Set in the then-future of 1973, Earth's space agency sends a rescue ship, the Challenge 142, to Mars. Their objective is to find the crew of the Challenge 141, which crashed and went silent. Upon arrival, they find only one survivor: Colonel Edward Carruthers.Because the rest of his crew is dead, Carruthers is arrested under suspicion of murdering them for food rations. He adamantly maintains that a hostile, indigenous Martian lifeform slaughtered his team. Naturally, the rescue crew does not believe him. However, just before takeoff, an open bay door allows a massive, bloodthirsty alien to stow away in the lower decks.

As the ship journeys back to Earth, the creature begins hunting the crew one by one, moving silently through the ventilation system and forced-evacuating the survivors to the upper decks. The crew of Challenge 142, led by Commander Van Heusen, finds Carruthers prepared to face a court-martial on Earth. They dismiss his stories of a Martian monster as a psychological delusion. In the lower cargo decks, crewman Kienholz is attacked, killed, and jammed into a tight space. The monster drains his body of all fluids. When the crew finds the drained corpse, they realize Carruthers was telling the truth.

The crew tries conventional weaponry to stop the beast. They use pistols, rifles, and even grenades, but the creature's thick hide shrugs off bullets and explosive damage. As the creature overpowers their weapons, the crew is forced to retreat room by room, sealing the hatches behind them. The monster uses the ship's large air ducts to bypass sealed doors, trapping crew members in darkness. Trapped in the final control room with dwindling oxygen, Carruthers notices that the creature's breathing increases when exposed to different air pressure. The survivors don their spacesuits and vent the ship's atmosphere into space. Lacking oxygen, the creature finally suffocates and dies.