Kraken

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

Pathfinder 1e Bestiary 1     Pathfinder original/official source

Pathfinder 2e Bestiary 1     Pathfinder original/official source

Mythic Monster Manual v1     Pathfinder original/official source

Mythical Monsters Revisted     Pathfinder (no source link)

Exotic Encounters     Pathfinder original/official source

Monster Manual     D&D 5e original/official source

Flee, Mortals     D&D 5e (no source link)

Creatures Of Vathis     D&D 5e original/official source

Monster Ecology Anthology     D&D 5e (no source link)

Monster Manual 3     D&D 4e (no source link)

Dragon Magazine Monster Ecologies     D&D 2e/3e (no source link)

QUERP Bestiary     QUERP original/official source

The Monster Overhaul     OSR (no source link)

Lairs And Encounters     Adventurer, Conqueror, King (no source link)

Baby Bestiary 2     Any original/official source