The recent advent of wide-field time-domain surveys has launched an upheaval in field of stellar evolution. These surveys are uncovering new types of astronomical transients that not only challenge existing models for supernova explosions but also our understanding of what physical processes can occur during the final years of a massive stars’ lives. Here I describe on-going efforts to constrain the explosion properties, progenitor systems, and intrinsic rates for several classes of peculiar astronomical transients and the implications for our understanding of stellar evolution. By opening new regimes of the dynamic sky, we have increased the variety of explosions we can directly probe, challenged our views of what mass-loss can occur in the final years before core-collapse, and expanded our knowledge of what final states are possible in the evolution of massive stars.