The Monsters Know What They're Doing     Dungeons And Dragons original/official source
Angry Golem (web)     D&D 5e original/official source
Pathfinder 1e Bestiary 1     Pathfinder original/official source
Pathfinder 2e Bestiary 1     Pathfinder (no source link)
Tome Of Horrors Complete     Pathfinder (no source link)
Mythic Monster Manual v1     Pathfinder original/official source
Monster Manual     D&D 5e (no source link)
Tome Of Horrors 2018     D&D 5e (no source link)
Monsters Of The Infinite Planes     D&D 5e original/official source
Monster Manual 2     D&D 4e (no source link)
D&D 2e Monstrous Manual     D&D 2e (no source link)
Monstrous Compendium: Al-Qadim     D&D 2e original/official source
Scruffy Grognard's Monstrous Manual     D&D 2e (no source link)
13th Age Bestiary     13th Age (no source link)
The Thousand Year Sandglass     Labyrinth Lord (no source link)
Fantasy Age Bestiary     Fantasy Age original/official source
Mystara Adversary Compendium I     Dragon Age original/official source
Monsters And Treasure (2019)     Castles And Crusades original/official source
Iron Falcon Handbook Of Monsters     OSR (no source link)
Baby Bestiary 2     Any original/official source