I can't watch the video cuz I'm missing plugins or somethin (can't read German) but the Japanese word for mole as in the animal is モグラ - Mogura but I'm guessing you mean in the sense of a sabotuer which is 二重スパイ - Nijyuu Supai (double (crossing) spy). I hope this helps?
Edit - Meh! the JF-Experts got here before me
