Atai Mons, Venus, is classified as a large volcano yet displays characteristics that are typical of coronae. Coronae are widespread volcano-tectonic features that are apparently unique to Venus. Detailed analysis of Atai Mons using photogeological and geophysical techniques illustrates that it has experienced a complex history and may still be active. We show that processes found at both coronae and large volcanoes have occurred throughout the history of Atai Mons with no definite temporal preference. It does not have an evolution that can be described simply as the evolution of one feature into another. These results suggest that large volcanoes and coronae are more intimately linked than previously thought, and that detailed mapping and gravity surveys are reliable ways of establishing the evolution of hybrid features.