The ghost can see 60 feet into the Ethereal Plane when it is on the Material Plane, and vice versa.
The ghost can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.
Withering Touch.Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 17 (4d6 + 3) necrotic damage.
The ghost enters the Ethereal Plane from the Material Plane, or vice versa. It is visible on the Material Plane while it is in the Border Ethereal, and vice versa, but it can’t affect or be affected by anything on the other plane.
Each non-undead creature within 60 feet of the ghost that can see it must succeed on a DC 13 Wisdom saving throw or be frightened for 1 minute. If the save fails by 5 or more, the target also ages 1d4 × 10 years. A frightened target can repeat the saving throw at the end of each of its turns, ending the frightened condition on itself on a success. If a target’s saving throw is successful or the effect ends for it, the target is immune to this ghost’s Horrifying Visage for the next 24 hours. The aging effect can be reversed with a greater restoration spell, but only within 24 hours of it occurring.
Possession (Recharge 6).
One humanoid that the ghost can see within 5 feet of it must succeed on a DC 13 Charisma saving throw or be possessed by the ghost; the ghost then disappears, and the target is incapacitated and loses control of its body. The ghost now controls the body but doesn’t deprive the target of awareness. The ghost can’t be targeted by any attack, spell, or other effect, except ones that turn undead, and it retains its alignment, Intelligence, Wisdom, Charisma, and immunity to being charmed and frightened. It otherwise uses the possessed target’s statistics, but doesn’t gain access to the target’s knowledge, class features, or proficiencies.
The possession lasts until the body drops to 0 hit points, the ghost ends it as a bonus action, or the ghost is turned or forced out by an effect like the dispel evil and good spell. When the possession ends, the ghost reappears in an unoccupied space within 5 feet of the body. The target is immune to this ghost’s Possession for 24 hours after succeeding on the saving throw or after the possession ends.
Source: 5srd adaptation of Pathfinder Roleplaying Game Bestiary.
When a soul is not allowed to rest due to some great injustice, either real or perceived, it sometimes comes back as a ghost. Such beings are in eternal anguish, lacking in substance and unable to set things right. Although ghosts can be any alignment, the majority cling to the living world out of a powerful sense of rage and hatred, and as a result are chaotic evil—even the ghost of a good or lawful creature can become hateful and cruel in its afterlife.
More than most monsters, a ghost benefits from a strong and detailed backstory. Why did this character become a ghost? What are the legends surrounding the ghost? An encounter with a ghost should never happen completely out of the blue—there are plenty of other incorporeal undead like wraiths and spectres to fill that role. A proper encounter with a ghost should be a climactic scene after a lengthy period of tension building with lesser minions or manifestations of the undead spirit.
When a ghost is created, it retains incorporeal “copies” of any items that it particularly valued in life (provided the originals are not in another creature’s possession). The original items remain behind, just as the ghost’s physical remains do. If another creature seizes the original, the incorporeal copy fades away. This loss invariably angers the ghost, who stops at nothing to return the item to its original resting place (and thus regain the item’s use).