Mole rat meat is most commonly found on the corpses of mole rats. It will restore a small amount of health, but also give a small dose of radiation. Mole rat meat is used in the crafting of mole rat wonder meat in Fallout 3 and mole rat stew in Fallout: New Vegas.
Mole rat wonder meat was first created in 2277 by a raider scientist named Ryan Brigg. According to his notes, mole rat meat becomes much more palatable after being cured in a metal box with wonderglue, producing a jerky which possesses a 'nutty aftertaste' and none of the natural bitter flavor.