Crystal Dispenser
From Tardis Wiki, the free Doctor Who reference
Crystal Dispensers, also referred to as Brothers, were male programmed robotic dispensers which only dispensed crystals. They appeared in different colours, including green, red, yellow, blue, orange and purple. They could project holograms that showed which colour crystal was required to fire at. They were found aboard the SS Lucy Gray, though for anyone who wasn't an engineer aboard the ship they would lower into the floor and hide. (GAME: Return to Earth)
