UNDEAD

Skeleton

The Monsters & Creatures Compendium     Any (no source link)

The Monsters Know What They're Doing     Dungeons And Dragons original/official source

Angry Golem (web)     D&D 5e original/official source

OSE Encounter Activity Tables     Any original/official source

Pathfinder 1e Bestiary 1     Pathfinder original/official source

Pathfinder 2e Bestiary 1     Pathfinder original/official source

Mythic Adventures     Pathfinder original/official source

Monster Manual     D&D 5e original/official source

Monster Manual Expanded v1     D&D 5e original/official source

Fifth Edition Foes     D&D 5e original/official source

Tome Of Horrors 2018     D&D 5e original/official source

Kobold Press Tome Of Beasts 2     D&D 5e original/official source

Old Gus: Plantfolk, Undead, And Other Oddities     D&D 5e original/official source

Limitless Monsters     D&D 5e original/official source

Monsters Of Feyland     D&D 5e original/official source

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

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

Monster Manual 2     D&D 4e (no source link)

Dungeons And Dragons Essentials: Monster Vault     D&D 4e (no source link)

D&D 2e Monstrous Manual     D&D 2e (no source link)

Scruffy Grognard's Monstrous Manual     D&D 2e (no source link)

Dragonlance Bestiary     SAGA (no source link)

Hacklopedia Of Beasts     Hackmaster original/official source

Monsters Compendium     Heroes Of Adventure (no source link)

Old World Bestiary     Warhammer original/official source

QUERP Bestiary     QUERP original/official source

Monsters And Treasure (2019)     Castles And Crusades original/official source

The Monster Overhaul     OSR (no source link)

Abnormal Undead     Any original/official source