Demons & the Sources of Evil
Demons, disease-bringers, and the restless dead prowled the unseen margins — held off by prayer, amulet, and rite.
Also: demons · demon · utukku · Lamashtu · Lamaštu · Pazuzu · evil spirits · the seven demons · ghost
Mesopotamians lived among unseen dangers: classes of demons that prowled the margins, the restless ghosts of the unburied or unhonored dead, and disease-bringing figures like Lamashtu, who threatened mothers and infants. These powers caused illness, nightmares, madness, and misfortune, often acting as the agents through which an angered god's protection, once withdrawn, was breached. Against them people deployed prayers, protective figurines, and the rituals of the exorcist; the fierce demon Pazuzu was even invoked to drive off Lamashtu. This was not mere 'superstition' but a coherent theory of why bad things happen and how order might be restored.
In short
The host of malevolent beings — demons (e.g. utukku, the seven), disease-bringers like Lamaštu and Pazuzu, and restless ghosts — that attack humans, and the divine and ritual defenses against them.
Where it’s found
The gallû-demons in 'Inana's descent' (ETCSL 1.4.1, in corpus); the Akkadian Udug-ḫul / Utukkū Lemnūtu incantation series, Lamaštu and Pazuzu texts (akkadian-pending)
How the idea developed across Sumer, Babylon & Assyria
The demonology is most fully developed in the first-millennium incantation series (Akkadian), though Sumerian incantations and the gallû-demons of Inana's descent are early. Lamaštu and Pazuzu are first-millennium-prominent. Present this as a coherent etiology of misfortune, not 'superstition.'