Rule 34 states: 'If it exists there is porn of it' and this website adds, 'If not, start uploading'. Rule34.xxx hosts a ton of different images and gifs, most of which are in the manga and hentai porn category. There are also stills from porn clips and movies.
There's no way of knowing exactly how much content is hosted on Rule34, but more are being uploaded each day. Photos and gifs include various characters from video games, cartoons, movies, etc., in explicit action. For example, you can find things like furry scat, dragon porn, Lion King group sex, and a whole host of other bizarre content, as well as some more traditional stuff featuring real porn stars. Moreover, you can also find lots of images that are safe for viewing.
Rule34.xxx has a simple and somewhat crude look to it. In terms of functionality, you can use a search bar to filter content and add or remove tags from a list, after which you can flip through pages with limited pagination. Furthermore, there is a list of artists, tags, aliases (to clarify certain things), and pools (themed groups). Bonuses include a forum, a link to Discord Chat (cross-platform text & voice chat app), as well as site stats and an iCame top 100 section which shows what users came to the most. If you find any of this confusing, you can read the help pages. On the subject of ads, there are just a few banners here and there.
If porn cartoons, manga, and hentai turn you on, you might wanna check out Rule34. It has all the photos and gifs you need to cater to a whole host of unusual kinks and fetishes, a few nice features, and a pretty active community.