True to Screen Rant's earlier prediction that a new playable monster D&D book was in development, Wizards of the Coast revealed Mordenkainen Presents: Multiverse of Monsters during the 'Future of D&D' panel at the conclusion of D&D Celebration 2021. Related: Dungeons & Dragons' Most Overpowered Character Builds - Skill Master These playable race rules were overhauled in Tasha's Cauldron of Everything in order to level the playing field across the board. The book Volo's Guide to Monsters features a lot of these, with some monsters featuring stat penalties. There were some rulebooks released after the Player's Handbook that included playable versions of the monster races. The Player's Handbook for D&D offers rules for several playable races, including humans, dwarves, and elves.
There are already several different rulebooks outlining playable monsters, and a complete curated and revised collection of those is finally on the way. The rules for Dungeons & Dragons' playable monster races will soon be overhauled, as D&D publisher Wizards of the Coast is updating them in an upcoming book: Mordenkainen Presents: Multiverse of Monsters.