One Piece: Taose! Kaizoku Ganzack
English title: One Piece: Defeat the Pirate Ganzack!
Japanese title: ワンピース 倒せ！海賊ギャンザック
Type: OVA
Source: Manga
Episodes: 1
Status: Finished Airing
Aired: Jul 26, 1998
Duration: 28 min
Rating: PG-13 - Teens 13 or older
Studios: Production I.G
Producers: Shueisha
Genres: Action, Adventure, Fantasy
Demographics: Shounen

While Luffy and his crew of Zoro and Nami are starving on their small boat, they are attacked by a large monster. Nami is taken away, while Luffy and Zoro wash up on shore. There they meet a young girl, Medaka, and learn of the sad history of the island. The evil Pirate Ganzack has taken away all the men in the village and enslaved them, including Medaka's father. Now Luffy, Zoro, and Medaka must infiltrate Ganzack's base in order to rescue the villagers and Nami. 

(Source: ANN)

One Piece: Taose! Kaizoku Ganzack was shown off at Jump Super Anime Tour in 1998 along side the Hunter x Hunter Pilot.