Teleportitis is the common name for the teleportation intrinsic/extrinsic that allows you (or forces you, depending on your viewpoint) to teleport randomly every few turns. It may be gained by eating a leprechaun, nymph, tengu, or Wizard of Yendor corpse, or by wearing a ring of teleportation (these are often cursed, so be careful). Teleportation via teleportitis works like other sources of teleportation, being blocked by no-teleport levels and sometimes by the Amulet of Yendor, controlled by teleport control, and landing you somewhere "safe".