Active M dwarfs produce explosive and frequent flares in line and continuum emission from X-ray to radio wavelengths. The primary mode of radiative energy release during stellar flares is through the optical and NUV continuum. However, this white light continuum arguably remains one of the least well understood phenomena during flares. I will show time-resolved spectroscopic and photometric observations of a white light megaflare that recently occurred on the dM4.5e star YZ CMi. This flare is one of the largest that has ever been observed on a low-mass star. The spectra show two prominent continuum components, and I will discuss the properties and time-evolution of each.