The pup soldiers (幼年兵, yōnen hei) is a group of wolf pups used by Gaia of the Army Of Black Wolf's Empire. They're around just one years old, and not afraid to die for their leader Gaia and the Underworld they live in.
A group led by Gin tried to get into Gaia's Empire to fight him. The pup soldiers attacked Gin and the group down the mountain to drag them into the lava below. They manage to get some of the group with them, like Suiga, while Akame manage to escape the grip of one of them and using his ninja skills to jump up. All the pup soldiers sacrificed their lives.