Koala is a prominent character in the anime series One Piece. She is a former slave who was freed by Fisher Tiger, a pivotal figure in the Fish-Man Island Arc. As a child, she was rescued from her captors and eventually joined the Revolutionary Army, where she serves as an officer. Koala is known for her compassionate nature and her commitment to freeing others from oppression. She works closely with Sabo, one of the main figures in the Revolutionary Army, and her background and skills make her an important ally in the fight against the World Government.