Watch out! Ghosts can appear and disappear when chasing you. They can also fly, so being on high ground isn't as useful. Ghosts deal 10-12 damage per touch. They have a walkspeed of 18, so they can outrun you if you don't have any speed gear. Hiding inside or behind cover would be another option to survive.
Hyper Ghosts is now always invisible with its doubled HP.
Deal ~20 damage, go faster, and can fly. They also insta-kill you when you kill them.