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!
Building a Classroom Community with a Student Photo Wall - Lessons With Laughter Ideas for modifying this for first grade in the comments. Could fit into 7 Habits, Responsive Classroom, rule making process, hopes and dreams, etc.