Cute, cute, cute! I would really use sushi rice for this and not white bread but hey, use approved bread or tortillas for the same effect.
Peanut butter, strawberry slices, and banana or something to that effect would be great as a sushi roll.
Or, peanut butter, thinly sliced celery and raisins for bumps on a log.
mmmmmmmmm, gonna try em out tomorrow.