The Monsters Know What They're Doing     Dungeons And Dragons original/official source
OSE Encounter Activity Tables     Any original/official source
Mythical Monsters Revisted     Pathfinder (no source link)
Mythic Adventures     Pathfinder original/official source
Flee, Mortals     D&D 5e (no source link)
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)
Monsters Compendium     Heroes Of Adventure (no source link)
The Monster Overhaul     OSR (no source link)