Pathfinder 1e Bestiary 2     Pathfinder original/official source
Pathfinder 2e Bestiary 2     Pathfinder original/official source
Tome Of Horrors Complete     Pathfinder original/official source
Forgotten Foes     Pathfinder original/official source
MojoBob (web)     D&D 2e original/official source
AD&D Fiend Folio     AD&D 1e (no source link)