OSE Encounter Activity Tables     Any original/official source
Pathfinder 1e Bestiary 3     Pathfinder original/official source
Tome Of Horrors 2020     D&D 5e original/official source
Faerie Bestiary     D&D 5e (no source link)
Critter Compendium     D&D 5e original/official source
Limitless Monsters     D&D 5e original/official source
The Book Of The Fey     D&D 5e original/official source