well, it's a TV promo trailer for the US version, though it does identify the jumbo shrimp as "Ebirah" when it's not named at all in the US version. whoever made this spot obviously knew what the original "international" title was, as there is a reference to "horror of the deep" in there as well. and doesn't that sound like the man who dubbed "Captain Mura" from Ultraman as the narrator?
I can't guarantee it, but this probably came from a DVD I put together several years ago of all the promos and trailers I could find. it featured mostly Japanese genre stuff, but Infra-man was there, as was Reptilicus. those were mostly for fun.