Preheat oven to 375° F
Place potatoes in a large pot.
Cover with water; bring to a boil and boil over medium high heat until potatoes are fork tender about 30 to 40 minutes. Remove pan from heat and drain well.
Add butter, milk, eggs, salt, pepper, green onions and bacon.
Whip on high with an electric mixer until potatoes are creamy or mash potatoes with a potato masher until creamy.
Set aside until cool enough to handle.
When potatoes are cool enough to handle, spoon potatoes into pastry bag and pipe potatoes onto a baking sheet sprayed with non-stick cooking spray, in the shape of ghosts.
Place two black sesame seeds, caraway seeds or flax seeds for the eyes.
Bake in oven until potatoes are light brown.