Dracopedia Bestiary: An Artist's Guide     Any original/official source
The Monsters Know What They're Doing     Dungeons And Dragons original/official source
Angry Golem (web)     D&D 5e original/official source
Atlas Animalia     Any original/official source
OSE Encounter Activity Tables     Any original/official source
Pathfinder 1e Bestiary 2     Pathfinder original/official source
Pathfinder 2e Bestiary 2     Pathfinder original/official source
Monster Manual     D&D 5e original/official source
Monster Ecology Anthology     D&D 5e (no source link)
MojoBob (web)     D&D 2e original/official source
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
Harnmaster Gold Bestiary     Harnmaster original/official source
Baby Bestiary 2     Any original/official source