Place the avocados in a mixing bowl and mash them with a fork until mostly smooth but still a little chunky.
Add the chopped eggs, mayonnaise, lemon juice, garlic powder, salt, and black pepper to the bowl.
Stir the mixture gently until the eggs are evenly coated and the filling holds together.
Slice the slider buns in half if they are not already split.
Spoon the avocado egg salad onto the bottom half of each bun, using about 2 tablespoons per slider.
Place two black olives on top of the filling to form eyes.
Add one or two red bell pepper strips below the olives to create a mouth.
Set the top bun in place and press lightly to hold the slider together.