Using Diels-Alders (DA) chemistry as a dynamic-covalent linkage, we explored the kinetic growth mechanism of polymer structures including starlike materials and nanogels. The use of reversible addition-fragmentation chain transfer (RAFT) polymerization allows for precise control of DA linkages within the polymer backbone. Controlling the competition between intra- and intermolecular cross-linking reactions allows for the preparation of polymer structures that can expand their volume after cleavage of the DA linkages as determined by dynamic light scattering (DLS). Macroscopically, this would be analogous to untying a rope ball knot, commonly termed a "monkey's fist".