Sparkly balls, small tennis balls, canvas or wicker balls filled with catnip, tiny stuffed animals. (thenoseprint.com)
There are many wood based toys that you can buy such as willow sticks and wicker balls as well as many free alternatives that will keep your rabbit amused and away from your house plants. (bunnyproof.com)
Untreated wicker baskets or other wicker items such as a wicker tunnel and wicker balls marketed for cats (thesprucepets.com)