Boil eggs in a saucepan covered with water for 10 minutes. Let cool for 10 minutes, then remove the shells. Slice each egg in half lengthwise.
Remove the yolks and place them in a small bowl. Mash together with the avocado; add salad cream until smooth. Spoon into a piping bag or a small plastic bag with a tiny corner cut off and pipe the mix into the egg cavities. Arrange them on a serving platter.
Place an olive slice in the centre of each egg and if you like, fill with a bit of mayonnaise. Use a toothpick to draw some red lines with ketchup to give the eyes a bloodshot look.