User blog comment:WolfyPearl/Story featuring all deleted animals?/@comment-28910924-20150708025811

See the category thing at the bottom of the page? Just click 'Add category', type in the name of the category you want to make, and press enter to create a category with the page in it. Or you could just create a page but put 'Category:' before the name of the page to turn it into a category page with no pages at the beginning. Example: 'Category:Deleted Animals'.