Why does kong look different
On the main page poster? He didn't look like that in the movie. Is there another version?
The films were released in several different versions - usually Japanese, American, and 'International' at a minimum, and some foreign markets put together their own versions of the posters.
Another reason - and the one that I think applies, in this case - is that if nobody uploads an original poster image to IMDB, they cobble them together from whatever images they DO have on-hand. Also, some of the poster/cover images that ARE uploaded come from cheapo VHS or DVD releases that didn't have the actual rights to the movie (AKA 'grey market'). Quite a few of the kaiju poster images on IMDB are faked-up.
- HOW kin I be so brainless, when I is so smart?