Attached to a root so appears to be a growth of some plant. In middle of lawn. But there are dead wild rose branches attached to the root. Hard but feels like it might be spongy inside. Can't pull from ground. Possible parasite type growth on damaged plant? There about 5 of these in the same area. Not a mushroom from looks of things due to fibrous single root. But all look the same. Some with insect holes all over.