The Eastern Watchdog is the Watchdog that replaced the corrupted Gulm and was seen being active during the film GARO Special: Demon Beast of the White Night. During this time, Rei was in charge of the East while Kouga was reassigned up North on a mission. The Watchdog gave Rei the assignment to head up North to assist Kouga because this year, the Eastern Makai Knight was responsible for over seeing the sealing of Legules during the Solar Eclipse. It is possible that during Rei's remaining active years as Zero, he would respond to this Watchdog. Eventually, he would be replaced by Jiiru.