Penguin is a character from the Katanagatari franchise.
Penguin Maniwa is a character in the Katanagatari series of light novels written by Nishio Ishin, a popular Japanese writer, with illustrations by Take. He also appears in the anime series of the same name which was created by White Fox and directed by Keitaro Motonaga. Penguin, voiced by Ryo Hirohashi, makes his first appearance in Episode #6 of the anime series: "Kanazuchi, the Twin Sword".
Penguin's ability is that of Unmei Kuzushi, probability manipulation, which allows him to survive situations that others would not and makes him near invincible against projectiles. He fights using a weapon called Juukyuu, a bouncing ball that constantly increases its speed when ricocheted off of a hard surface. Despite its rubber-like properties, it is sharp enough to cut an opponent when contact is made. When used in an enclosed area, the device essentially becomes a death trap, never hitting Penguin because of his abilities but slowly whittling down the health of his opponent.
Emonzaemon faced Penguin and found himself trapped in this situation but was able to overcome it by using Entou Jyuu to ricochet bullets around the area in hopes that Penguin's luck wouldn't allow him to avoid the constant barrage of bullets and his own weapon.