Mamonogurai no Boukensha: Ore dake Mamono wo Kuratte Tsuyoku Naru

Rudd earned his nickname “Grubby Gorager” because of the unwanted smell that he got during a deadly mission of collecting herbs in the Noxious Labyrinth. Other teammates always disliked him, which is why they abandoned him during a monster attack. Trying to survive, he eats a monster and unlocks a powerful new ability.