We demonstrate how simple local sensing and control rules achieve useful emergent behaviors in modular self-reconfigurable (metamorphic) robots. Our biologically inspired approach grows structures with the desired functionality even though the final shapes have some unspecified random variation. By contrast, other self-reconfiguration algorithms require an a-priori exact description of a target shape for the given task, which may be difficult when a robot operates in uncertain environments. We present and evaluate several control algorithms through simulation experiments of Proteo, a metamorphic robot system.