Luffy Submerged! Zoro vs. Hatchan the Octopus!

Synopsis

Arlong has trapped Luffy in the ocean and Zoro faces the six-sword–wielding octopus Hatchan. Using Johnny and Yosaku's swords and fighting through his injuries, Zoro is able to defeat Hatchan. (Source: Wikipedia) East Blue saga: Arlong Park arc: (9/14)