Rabbit toys should be safe. Rabbits can ingest plastic. Cardboard boxes are great to chew and climb in and out of. Old telephone books are fun to play with and shred. Parrot toys make equally good rabbit toys.
Rabbits love baby toys like sturdy plastic keys.
Cat cubbies and condos with ramps and lookouts are great for rabbits. Save the large tops off of laundry detergent and laundry softener bottles. Wash these tops well. The tops are wonderful to hold on to and haul around. Large balls are fun to roll around.