Cerberus

The Cerberus is a three-headed lower level, dog-like monster from the 1st wave (or a two headed dog-like monster that is found Coal Mine near Melromarc in the manga). It is responsible for unlocking the Cerberus Shield. The Cerberus Shield is used for close ranged counter attacks. A pitch black, three-headed Cerberus is recollected as the one that killed Raphtalia's parents during the 1st wave. In the manga, the battle with a two headed Cerberus allows her to trust Naofumi to protect her. Found in 『Chapter 19』 of the web novel and 『Manga Volume 1 Chapter 4』.