Pathfinder 2e Bestiary 1     Pathfinder (no source link)
Pathfinder 2e Bestiary 2     Pathfinder original/official source
Tome Of Horrors Complete     Pathfinder original/official source
Critter Cache: Animals And Beasts     D&D 4e original/official source
Frostburn     D&D 3e original/official source
Hacklopedia Of Beasts     Hackmaster original/official source
Hacklopedia Of Beasts Vol 1     Hackmaster original/official source