Yes, he was introduced in Shi No Numa and he's been on every map since then besides Call of the Dead. He plays an integral role in the whole backstory of Nazi Zombies, and he's extremely entertaining in the game. XD
Wll, one can't have a good Nazi Super Science story without a high-ranking sadistic Nazi! Unless there aren't zombies or human experiments involved. Or giant robots, or...ok, they all need one. XD