The Sleepers of Sheltem are characters in Might and Magic III: Isles of Terra. They are spirits that Sheltem sent out across Terra to find mysteries and myths. They reported all the secrets they had learned to Sheltem.
In the chambers beneath Terra's pyramids there were eight crystal lions, intended by the Ancients to store dead Guardians to ensure that their knowledge was not lost. Sheltem imprisoned the Sleepers in the crystals to store the knowledge they had gained. He also imprisoned some of the Sleepers in ancient stone heads.
Sheltem set the ED-409s, iron wizards, mystic clouds, and guardians to protect the Sleepers. Once, a group of heroes entered the pyramids and learned many secrets from the Sleepers, but Sheltem killed them and placed their heads on spears in Shadowmire. He also cursed them to spend the rest of eternity babbling, unable to share the secrets they had discovered.
Foerdhal the Erudite also entered the halls the great secrets, but the Sleepers were so eager to have a mortal form again that they crowded into Foerdhal's mind, driving him insane. Foerdhal rampaged through the halls, destroying much of the underworld, and accidentally capped the flow of the Fountain of Nayarah. Sheltem sent his armies against him, since the Sleepers were pouring into Foerdhal's mind, robbing Sheltem of his secrets. In addition, the Ancients were angered by the destruction of their underworld, and sent their own army against Foerdhal, and he was crushed between the two armies.