Creature type (Dungeons & Dragons) all animal type monsters are based on real world animals. Creature entries based on mythological, fictional, or nonexistent animals are usually classified as magical beasts (see below). Besides ordinary fish, birds, reptiles and mammals, the animal type is also applied to depictions of dinosaurs, prehistoric animals, and "dire" or specially modified, often larger and scarier, versions of real world animals. Some real world animals are not given the animal type in the game. Examples include arthropods (insects, spiders, etc.) and worms, which the game classifies as "vermin" (see below) and not animals. Mollusks, such as octopuses, are often classified as
Creature Catalogue found in the Basic, Expert, Companion and Master rulesets. Each creature in the book is illustrated, and the entries in the book are ordered by type rather than just alphabetically. This includes six sections: Animals (including giant and extinct varieties), Conjurations (such as elementals and golems), Humanoids, Lowlife (including insects, plants, and jellies and slimes), Monsters (a catch-all category), and Undead. The Intelligence score of each monster is listed with the rest of its statistics. The book also includes a comprehensive index of all monsters by environment, and Frank Mentzer's guide on how to balance encounters according to the levels