The Monsters & Creatures Compendium     Any (no source link)
The Monsters Know What They're Doing     Dungeons And Dragons original/official source
Monstrosities     Swords & Wizardry 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 original/official source
Monster Codex     Pathfinder original/official source
Mythic Monster Manual v1     Pathfinder original/official source
Giants Revisited     Pathfinder original/official source
Monster Manual     D&D 5e original/official source
Monster Manual Expanded v3     D&D 5e original/official source
Flee, Mortals     D&D 5e (no source link)
Volo's Guide To Monsters     D&D 5e original/official source
Monster Manual 3     D&D 4e (no source link)
Monster Manual 2     D&D 4e (no source link)
D&D 2e Monstrous Manual     D&D 2e (no source link)
Scruffy Grognard's Monstrous Manual     D&D 2e (no source link)
Role Aids: Giants     AD&D 1e (no source link)
13th Age Bestiary     13th Age original/official source
Hacklopedia Of Beasts Vol 3     Hackmaster original/official source
Hacklopedia Of Beasts     Hackmaster original/official source
Godforsaken     Cypher System (no source link)
Lairs And Encounters     Adventurer, Conqueror, King (no source link)