Monstrosities     Swords & Wizardry original/official source
Angry Golem (web)     D&D 5e original/official source
OSE Encounter Activity Tables     Any original/official source
Pathfinder 1e Bestiary 1     Pathfinder original/official source
Pathfinder 2e Bestiary 1     Pathfinder original/official source
Monster Manual     D&D 4e (no source link)
Sword & Sorcery Creature Collection     D&D 4e (no source link)
Critter Cache: Prehistoric Beasts     D&D 4e original/official source
D&D 2e Monstrous Manual     D&D 2e (no source link)
Scruffy Grognard's Monstrous Manual     D&D 2e (no source link)
AD&D Monster Manual     AD&D 1e (no source link)
Dragonlance Bestiary     SAGA (no source link)
Hacklopedia Of Beasts     Hackmaster original/official source
QUERP Bestiary     QUERP original/official source
Manual Of Monsters     Amazing Adventures (no source link)
Mystara Adversary Compendium I     Dragon Age original/official source
Monsters And Treasure (2019)     Castles And Crusades original/official source