More on Grave Searchers from Infoplease:

• Grave Searchers - Grave Searchers Monkir and Nakir, so called by the Mahometans. (Ockley, vol. ii.) (See Monkir.) ...
• Dictionary of Phrase and Fable: G - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "G"