Effriax is a Specter Panther, a breed of cat based off of a Dungeons & Dragons monster.

Effriax is the leader of the Nightmare Squad for a good reason. Specter Panthers' food is the fear of others.

His metallic hand is grafted on since his original hand was torn off from a battle with a Warrior Behemoth.

Nearly forgot to mention this... Effriax was named by my friend, Lorepath, the husband of Helen Galvin AKA Pink Fairy Lotus.