A movie doesn't just plop out of a writer's or director's imagination fully formed. It is the end result of hundreds of changes and tweaks and revisions, which is why, for instance, many of your favorite movies started from utterly ridiculous scripts.
It's the same for movie monsters -- it's hard to imagine the Predator or Jabba the Hutt as anything other than the iconic beasts we know and love. But they and others evolved from ideas that at the concept stage were very, very different. And very, very stupid.
6Star Wars -- Jabba the Hutt Was an Irish Space Furry
It's hard to imagine it now, but for a long time Star Wars fans had no idea what Jabba the Hutt looked like. He's mentioned in the first two movies, but never shown -- all we knew was that he was some guy Han Solo owed money to. When George Lucas finally unveiled the character in Return of the Jedi, fans everywhere went "Yep, that looks like a Jabba all right."
"He's got the gravy-sweats and everything."
But what if they had included him in the first movie, which had a considerably smaller budget? Would Jabba have looked as imposing and intimidating as the giant slug monster he turned out to be?
Well, that depends on how scared you are of fat Irish people in fuzzy clothes:
Star Wars Wikia
Jabba. Far right: Freshly shaved Chewbacca.
Yep, that's Northern Irish actor Declan Mulholland playing "Jabba the Hutt" in a deleted scene from A New Hope. This was never supposed to end up in the finished film, though: The plan was for Lucas to lay a stop-motion creature over Mulholland's performance ... keeping the thick Irish accent and all. This, of course, doesn't explain why the guy is dressed in that ridiculous costume -- maybe it was there to help Harrison Ford visualize the character, or maybe it's just what the actor came in wearing that day.
Star Wars Wikia
We assume all Irish people dress like this all the time.
So what would the finished version of Jabba have looked like? Something like this:
Your eyes do not deceive you. That's a slug violating an Irishman.
According to Lucas, he originally saw Jabba as "a big furry character," as opposed to the lovable slug we all know. That's right: Jabba the Hutt was dangerously close to being some sort of mean, morbidly obese Ewok. What Lucas has never explained, as far as we know, is why he chose to make him sound like an Irish gangster. We could be witnessing the first steps on the road to Jar Jar Binks here.
As fans well know, Lucas eventually included the deleted scene in the special editions, awkwardly inserting a CGI version of the Return of the Jedi Jabba and redubbing the dialogue. We kind of wish he had gone the other direction and instead CGI'd the fat, furry Irish guy into Jedi. Seriously, imagine Slave Leia strangling him.
Our statisticians estimate that four of you are now masturbating.
5Predator -- The Predator Was Jean-Claude Van Damme in a Rubber Suit
The Predator is a slightly bizarre character, when you think about it: It's like a futuristic Rastafarian jungle commando with a dissected crab for a face, but the weirdest part is that this strange combination of elements actually works. Then again, its eclectic design was probably the product of a lot of careful study and consideration. Right?
Actually, it was sort of thrown together at the last moment -- and before that, this is what they were going with:
It's a ... space duck warrior. The version you see here was a lot slimmer, shorter and generally less badass than the final one. It was also extremely clumsy -- if you still think it doesn't look too bad, that's because you haven't seen it prancing around the jungle like an idiot:
What you're looking at there is the red version of the suit that they used to shoot the camouflage scenes -- and that's actually Jean-Claude Van Damme in it. Yup, they hired a pre-Bloodsport JCVD to be the Predator because apparently they wanted it to have a ninjalike quality (which means they were just throwing shit at the wall and seeing what stuck). They were actually halfway through the movie when director John McTiernan fortunately realized this wasn't working out and tossed the costume in the trash.
Cave Above the Mansion
Also, the guy in it.
The Predator we know came about more or less by accident. Without a monster and feeling pressured by the studio, McTiernan desperately called special effects wizard Stan Winston (who had worked on the first Terminator film) and asked him to come up with a new version. Winston was literally sketching some ideas in the plane when the guy sitting next to him suggested that some mandibles might look cool. Sure, that dude happened to be James Cameron, but still -- that's some last-minute shit right there.
"... but I'm gonna pass on making it a blue cat person, Jim."