They should have the dig settings of Monty moles
(If they spawn buried or not, and if they create a hole after exiting a semisolid).
When they spot you, they roll after you at the speed of a goomba.
When hit with any attack (excluding the tanooki statue) they become dormant rocks that can be thrown like mushroom blocks. They shouldn't bounce, however
After a while, they come back, and damage you, if you're holding them.
Maybe making them separate requests will make them less imposing.