Possible Clues:

• Campy 1958 sci-fi film, with 'The'
• Amorphous splotch
• Sci-fi monster
• Sci-fi alien of '58 (with "The")
• Oozing monster of 1958
• Amoeba, e.g.
• Mass
• Drop of thick liquid
• Indistinct, shapeless form
• Amorphous monster