The Monsters Know What They're Doing Dungeons And Dragons 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 5e original/official source
Monster Ecology Anthology D&D 5e (no source link)
Monster Manual D&D 4e (no source link)
Dungeons And Dragons Essentials: Monster Vault D&D 4e (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)
Godforsaken Cypher System (no source link)