You can use any shape. It doesn't have to be a bunny. Just trace a shape or cookie cutter. This would be cute for any holiday, just use an appropriate cookie cutter to trace and cut out the shape, then whatever yarn works best for that holiday!
Once baked, salt dough can last for years, making these Easter egg ornaments a wwonderfully cheap way of decorating for Easter. With a bit of clear varnish, they can even be hung outside! Amy Christie explains how to make them. Why not get the kids to help you decorate them, for personal, memory-filled decorations that you can bring out year after year?