User blog comment:ScreamKings/HELP!/@comment-303594-20160517114941/@comment-303594-20160517132251

Sure.

Simply edit the page of the images you want to add to that category and type Images to add them to the category, then save the page. You might also have to create a page for the category itself. Once you've added the page to the category click on the category, which will take you to the category page for it (listing all the pages in the category) - for example on my test wiki it's http://testtube.wikia.com/wiki/Category:Images

Then just hit the create button and type a small description and save.