Best space monsters from the 1950s

What do you mean by "Space monsters"?

Do you mean monsters (large destructive animals) that come from outer space or live in outer space?

Or do you mean nonhuman people who come from outer space, often with hostile intent toward Earth humans?

Large, violant, animals in or from outer space feature in:

Cat Women of the Moon (1953) - Giant spiders on the Moon.

The Quatermass Xperiment (1955) - an astronaut from Britain mutates into a monster that could destroy humanity.

20 Million MIles to Earth (1957) - A reptile-like animal from Venus.

The Giant Claw (1957) - A giant bird-like creature from outer space that some people think really "rocs", though others call it a turkey.

The Blob (1956) - A rapidly growing man-eating blob from outer space.

It! The Terror From Beyond Space (1958) - It is either a violent Martian animal or a violent Martian person.

Missile to the Moon (1958) - humanoid shaped rock monsters on the Moon.

Angry Red Planet (1959) Several Martian monsters.

First Man into Space (1959) - A returning astronaut turns into a dangerous monster.

Teenagers from Outer Space (1959) - Aliens plot to release gargons, giant lobster-like monsters, on Earth.

And those are about all of the monsters in or from outer space I could find in 195s movies.

I think that most of the really great monsters in 1950s movies originated on Earth. In any case, those are the examples of large, violent space animals to choose the best exampls from.

To be Continued:

Continued:.

Here is a list of some of the best and most out of this world extrterrestrial people in 1950s films.

The head Martian invader in Invaders from Mars (1953), carried around in a glass sphere by the Martian foot soldiers.

The aliens in It Came from Outer Space (1953).

The Martians in The War of the Worlds (1953).

The Metalunan mutants in This Island Earth (1955) are supposed to be sub intelligent, but they have giant brains and might possibly be oppressed people.

Moviegoers might try to imagine what the Krell looked like from a few clues in The Forbidden Planet (1956).

It had an interesting design in It Conquered the World (1956).

The aliens in Warning from Space (1956) were genuine "starfish aliens" https://tvtropes.org/pmwiki/pmwiki.php/Main/StarfishAliens

The Brain from Planet Arous (1957) definately didn't look like a human.

The aliens in Invasion of the Saucer Men (1957) had a humaoid shape but were highly non human looking.

The aliens in I Married a Monster from Outer Space (1958) were also humanoid but very exotic.

The alien in The Space Children (1958) is alien.

The aliens in The Crawling Eye (1958) are among the best.

The Angry Red PLanet (1959) had Martian monsters and I think a Martian person.

The alien in The Atomic Submarne (1959) is good.

Wow I need to see this flick!