or Kamakira as Ichiro calls the bug in Godzilla's Revenge (1969). the monsters go by "Gimantis" in the US TV version.
the praying mantis is a fascinating creature and really beneficial one. of course, when you are stranded on a island and suddenly you are confronted by several giant ones, you might change your mind about that.
this is what happens in the fun island adventure called Son of Godzilla (1967). scientists doing weather experiments cause several giant mantis to become enormous. oddly enough, they were on the island before the scientists got there (as well as the egg Minya is hatched from and the giant spider Kumonga (aka Spiga/Spigon).
Kamakiras is brought to life by marionettes, and they look great. the colors and details are wonderful, a great testament to the craftsmen of Toho Studios.
I first saw the mantis monsters in the aforementioned Godzilla's Revenge in about 1973. they are mostly stock footage from Son Of Godzilla, but since I hadn't seen that movie yet they were all new to me. in that one they menace both Minya and Ichiro (in some newer footage) and in the surrealistic styling of the movie are quite scary.
The Deadly Mantis (1957). this movie follows the standard "monster gets unfrozen by a bomb" story and is decently entertaining. the monster isn't a patch on what Toho would do ten years later though!