As of 2015, A-Z-Animals.com, Skyenimals.com, TheLists.org, AlphaLists.com and TheFreeResource.com offer alphabetical lists of animals. These sites do not require users to log in to access information. Some of the sites offer more information about the animals, such as kingdom, class and genus.
A-Z-Animals and Skyenimals offer quizzes and games that help users learn about the animals. Skyenimals has pictures of all the animals on its list. Alphabetical lists of animals may contain animals of different species and classifications. There are about 9 to 10 million species of animals on earth, according to EOL.org. Animal classification depends on habitat, body structure, type of feeding and other features.