This category will mostly be for kaiju such as Godzilla, but it can also include movies about any sort of giant monsters, including giant humans and robots, as well as giant animals/creatures of any sort. What it will not include is roughly human-sized monsters such as vampires, werewolves, ghosts, mummies, zombies, or anything like that. For such things, you should look to categories like monster movies, scary movies, supernatural & paranormal, and possibly science fiction or fantasy. Maybe even weird movies. I should also say that most- or possibly all- giant monster movies will basically be a cross between science fiction and horror, so I could very well put my reviews in either one of those categories instead of even having a "giant monster" category, but I wouldn't be particularly comfortable with that. So, whatever. I've made this category. I'm not sure how much stuff I'll put in it, because I don't actually watch a lot of giant monster movies, but... there are some I'd certainly like to get around to watching, eventually. (Some time after creating this category, I also created a category for B-movies, which I think most giant monster movies would be, but I still like having a separate category for these films.)
Oh, for an idea of movies that could qualify for this section, you should check out Wikipedia's list of giant monster films. There are way more movies on that list than I'm ever gonna watch (from this genre), but some of them I will. There are also some there that I'll put reviews of in other sections instead of here, for whatever reasons. But, anyway, you know... it's a good list.