Zang Roo is a zombified version of Kang Roo. She has significantly higher stats, as well as the zombie-type abilities, burrowing and respawning. It is recommended to 'waste' one of her burrow abilities by either killing her before she burrows, or tricking her into burrowing underneath a weak cat, away from your other cats. Like Zory and all of the other zombie enemies, Zang Roo respawns at full health, one time. Never underestimate 2 of her in Multiversal Studios or 30 OF HER IN Lovechild lane.
After 50 years as a boxer, her body just couldn't handle the doping anymore. Still, chemicals were effective enough to keep her body punching even after death.