My rabbits all time favorite toy is cardboard boxes! We collect all the cardboard boxes that we get from getting stuff delivered to the house, and even have a few friends who donate their boxes to us.
I use the boxes to make them things like tunnels, and box forts. They have a great time hiding in the boxes, sleeping in them, chewing them up. When they get old and destroyed, I just throw them away and replace them.
With my bunnies other toys, I rotate them once a week so they don't get too bored with them. They have balls with bells, wooden toys they can chew, balls, rattles, stuff like that. One of my boys loves this plastic ball that has a bell in it. They all really like toys made out of unpeeled willow, but those never last long before they get destroyed.
You can put hay and a few treats into a toilet paper roll and give him that. If you have any really small boxes, you can close them up with treats inside.