...
Possessed cabinets are the simplest form of enemies found in the game. A possessed cabinet jumps up and down in regular intervals. The speed, regularity and height of their jumps may change from cabinet to cabinet. In the later levels the cabinets act more unexpectedly and may change their speed, jump regularity and jump height at any given time.
The Wanderer 
The wanderers are grumpy ghosts that insist on pestering Winston whenever they can. A wanderer can fly anywhere in the level - even through walls and floors. The Wanderers have no advanced AI. They simply move from one screen side to the other, much akin to the "ball" in the classic Pong -game.
Wanderers may randomly appear out of nowhere at any given time. They fly around the screen for 20-30 seconds before fading away. In the later tougher levels the wanderers may be there from the very beginning of the level and never disappear.
Ghost dog 
The ghost dog runs back and forth the hotel corridors. When encountering a wall or other obstacle the ghost dog changes its direction of movement.
...