SRD:Cloak of Poisonousness
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Cloak of Poisonousness: This cloak is usually made of a woolen material, although it can be made of leather. A detect poison spell can reveal the presence of poison impregnated in the cloak’s fabric. The garment can be handled without harm, but as soon as it is actually donned the wearer is killed instantly unless she succeeds on a DC 28 Fortitude save.
Once donned, a cloak of poisonousness can be removed only with a remove curse spell; doing this destroys the magical property of the cloak. If a neutralize poison spell is then used, it is possible to revive the victim with a raise dead or resurrection spell, but not before.