Creature Chronicle (web)     Pathfinder original/official source
Monsters Of Feyland     D&D 5e original/official source
D&D 2e Monstrous Manual     D&D 2e original/official source
Scruffy Grognard's Monstrous Manual     D&D 2e (no source link)
Hacklopedia Of Beasts Vol 4     Hackmaster original/official source