Start the quest by speaking to Moneo Fuente. Fuente says that he likes to collect animal horns since they contain the soul of the animal. Fuente is particularly interested in the precious Knocking Rupia horn. He requests that you bring him 5 Knocking Rupia Horn. Head east to Feather Plain and kill Knocking Rupia to collect the 5 horns. Return to Fuente to receive your reward.