Cerberus

Cerberus doesn't speak.

Cerberus is a ginormous, kaiju-sized, monstrous-looking three-headed dog with a muscular physique, black fur, short cropped ears, fiery red eyes and a thin tail. His heads are identical to each other as they each sport the same enormous mouths and razor-sharp teeth while his appearance bares a strong resemblance to that of a Beauceron.

Cerberus has an aggressive and feisty personality, but will obey his master, Hades, whenever he is called. However, he will retaliate if Hades beats him too much. Like the character from Greek mythology, he still guards the entrance to the Underworld, preventing dead souls that have crossed the River Styx from escaping.