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)
Encyclopedia Of Lifeforms Mundane And Magical     D&D 3e (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)
The Thousand Year Sandglass     Labyrinth Lord (no source link)
Fantasy Age Bestiary     Fantasy Age original/official source