Prepare sushi rice according to package. Allow rice to cool until it can easily be handled.
Using your hands, shape 1/4 cup rice into small mound (mouse shape).
Cut the green portion of green onions into 2-inch slices. Add one to each mound to be the mouse tail.
Add two sesames for eyes.
Using a potato peeler or paring knife, peel 1/2 inch of the cucumber skin. Add two slices to be the mouse ears.
Serve on top of a seaweed sheet with sliced peppers and avocados.
Notes
Alternative: You can also roll up your peppers, avocado, and any additional toppings inside of your rice mouse bodies. I just find it easier to keep them on the side allowing your sushi mice to be customized.