Talloon is an emerald dragon disguised as a human.
Talloon is first seen in chapter 5 where he meets Phodom and Fradz. He can be fought and is an Elite Boss of the chapter. After losing the match, Talloon shares more information about the world and dragons, but warns the Dragon Slayers not to tell anyone that he's in reality a dragon.
Eventually Phodom and Fradz come back with some soldiers, attempting to defeat Talloon. Talloon responses by flying away.
It's not known yet how powerful Talloon can be, but it is widely speculated that he'd have immense powers in reality.
Talloon is known to be a modest, yet very talkative person. He's usually helpful and full of joy, but sometimes he gets cold and cares less about the loved ones.