From Halopedia, the Halo wiki

Dream-shapers are a drug or mechanism once used within the Covenant's fleet to keep crewmen alert for their tour, in conjunction with stimulants. For example, dream-shapers were used aboard Ceudar-pattern heavy corvettes by the crew to stay alert for their tour, as the corvettes had no long-term accommodations.[1]


  1. ^ Halo: Warfleet, p. 76