I made this bunny when I was in 2nd grade! When I taught 4th grade I made them with my students each year. My sister made them with her kids a few years ago, and they love comparing these to the ones we made as kids. It is super-easy!
Thoroughly wash the inside of a small milk carton, the size they use in schools or 1/2 pints of cream. When it is completely dry, glue the top back together. Lay it on its side and cut a trap-door into one side so it has a compartment in the bunny's back.
Decorate with cotton balls, felt, pom-poms, and googley eyes. You will also want to put a little felt tab on the trap door to make it easier to open. Be sure to use a craft glue like Aleen's or Sobe. Regular white glue will just soak into the materials and not stick. I tried making this with batting instead of cotton balls once, but it didn't look as fluffy. Before you glue down the cotton, pull them apart a little to make them fluffier.
This could just be a cute decoration, but you could also fill it with some Easter grass and candy as a little hostess gift, or for an egg hunt make one for each child that they find in addition to the eggs and it has a bigger surprise in it.