The Pac-Man Ghosts are Easter Egg enemies only found in Wolfenstein 3D levels Episode 3, Floor 10 & Episode 6, Floor 10 and are part of the remake of the first level of Pac-Man; Blinky makes a surprise appearance in E6L10. These Pac-Man Ghosts cannot be killed or stunned with any weapon and they drain your health alarmingly fast by touching you. Even one can kill a completely healthy player in two to three seconds.
In the Mac Family they have a more textured, three-dimensional appearance. One of them is colored green instead of orange. They also share little resemblence to the actual Pac-Man ghosts contrary to the MS-DOS version.
In the PS3 and Xbox 360 ports, the Pac-Man ghosts are replaced by Fake Hitlers, most likely due to copyright issues. (Blinky still appears in E6L10)