Pulsating White Dwarfs in Cataclysmic Variables: The Marriage of ZZ Cet and Dwarf Nova

There are now four dwarf novae known with white dwarf primaries that show large amplitude non-radial oscillations of the kind seen in ZZ Cet stars. We compare the properties of these stars and point out that by the end of the Sloan Digital Sky Survey more than 30 should be known.