Oileus.

Oileus (Ὀϊλεύς) (Oī̈leús) was known as the king of Locris (Λοκρίς) (Lokrís) in Greek mythology. Also, he was an Argonaut (Ἀργοναῦται) (Argonaûtai). 

Hodoedocus (Ὁδοίδοκος) was Oileus' father. Agrianome (Ἀγριανόμη) was his mother.

Oileus had a wife named Eriopis (Ἐριῶπις). They had a son Ajax (Αἴας) (Aias) the Lesser.

Oileus was wounded in the shoulder by Stymphalian Birds (Στυμφαλίδες ὄρνιθες) (Stymfalídes Órnithes).

Slay the Stymphalian Birds.

The Stymphalian Birds were wild and dangerous animals. They could eat people. Birds had weapons, metallic feathers.

Goddess Athena helped Heracles with this labour. She gave him krotala. Zeus's son shook it and shot birds. Heracles used arrows with Lernaean Hydra's blood.

So, Heracles did his sixth labour.