The Strange World of Planet X

As a very young lad in the late 50's with an older sister who had a car, I spent many a Saturday with her and her friends at the local movie theater watching the latest horror movies.She says this was my choice because I did'nt like Westerns. Well I can't remember that but I do vaguely remember a certain double feature that scared the hell out of me. When I got home I did not want to go to bed(our house was in the country with woods all around). I thought the real frogs,crickets, and other bugs I heard outside were giant insects coming to get me. Since that night some 45 years ago I have seen countless 50's SF and horror movies hoping to find out what those 2 movies were. Many were similar and some had similar names ie."Thing From Another World", "Monster That Challenged The World"(I also saw it when I was a little older but it did not scare me quite as much),"X The Unknown","The Beginning Of The End" etc. but none were exactly "right".I began to think these movies did not exist or had gotten lost so I just gave up ever finding them, especially since no tv station we get ever shows any old SF or horror movies anymore.Since I had no idea of their titles(if they did exist) or actors in them , I logged on to the imdb and starting reading reviews of some of the movies and BINGO!!!There they both were. I could not believe it.Thanks to the great descriptions by your reviewers I finally found them. Needless to say they have both been ordered. The scariest to me was "The Strange World of Planet X", probably called "Cosmic Monsters" or "Crawling Terror". I can't give a a decent review of either movie because it has been 40+ years. By the way the other goodie was "The Trellenberg Terror" aka "The Crawling Eye" or "The Creature From Another World" . Now my life will be even more complete (ha ha) when someone comes out with a DVD or VHS of "Caltiki ,The Immortal Monster".I did catch it on tv as an "adult" of about 14 years of age but have not seen it since.