In one of Philip Pullmans His Dark Material novels there is a race of creatures that have a symbiosis with a tree whose huge perfectly round nut can be grasped by their fore and hind limbs and they roll around that way.
In one of Philip Pullmans His Dark Material novels there is a race of creatures that have a symbiosis with a tree whose huge perfectly round nut can be grasped by their fore and hind limbs and they roll around that way.
One of the Animorphs spin offs had them too, it was meant to be specifically genetically engineered or something from distant memory.