I summoned a Stardust Dragon to kill the Ghandis.
Floor 249 contains 100 Eyes of Cthulhu, 50 Eaters of Worlds, 50 Brains of Cthulhu, 50 Skeletrons, 50 Queen Bees, 25 Walls of Flesh, 25 Destroyers, 25 Skeletron Primes, 25 pairs of Twins, 18 Planteras, 18 Golems, 12 Duke Fishrons, 12 Lunatic Cultists and 6 Moon Lords.