Cut eggs in half lengthwise. Remove yolks and place in medium bowl. Set whites aside.
Mash yolks with fork; stir in mayonnaise, mustard, salt and pepper.
Pipe or spoon egg yolk mixture into egg white halves.
Transfer ketchup to resealable bag. Snip off corner. Pipe ketchup onto egg white to resemble veins in blood shot eyes.
Place one olive into the center of each yolk to resemble an eyeball. Serve immediately or
store in refrigerator for up to 2 days