* The Monster Manual: The Monster Manual is the official sourcebook for monsters in Dungeons & Dragons. It contains over 300 monster templates, each with detailed statistics and descriptions.
* Volo's Guide to Monsters: Volo's Guide to Monsters is a supplement for Dungeons & Dragons that expands on the Monster Manual. It contains over 200 new monster templates, as well as information on monster lairs, habitats, and behaviors.
* Mordenkainen's Tome of Foes: Mordenkainen's Tome of Foes is another supplement for Dungeons & Dragons that focuses on monsters from the outer planes. It contains over 100 new monster templates, as well as information on the cosmology of the Dungeons & Dragons setting.
* Xanathar's Guide to Everything: Xanathar's Guide to Everything is a catch-all supplement for Dungeons & Dragons that includes a variety of new player options, as well as a section on creating custom monsters. The section on custom monsters provides guidance on designing monsters of different challenge ratings, as well as tips on creating unique and interesting monster abilities.