Episode of Merry

Episode of Merry: The Tale of One More Friend is a TV Special of the One Piece anime. It aired after Episode 608.

The story arcs aboard the Straw Hat Crew's first ship Going Merry are recreated with brand-new animation, from Luffy and Usopp's fight and Robin's disappearance to the crew's final farewell to the ship.

Short Summary
During a lull in their travel, the Straw Hats are milling around the Sunny. Usopp, Chopper, and Brook head out to explore the surrounding ocean in the Mini Merry II. Brook asks about the Merry, having joined after the crew had acquired the Sunny. To which Usopp and Chopper then go on tell him about the Merry, from her journey from Syrup Village to the events leading up to it unfortunate demise during the Water 7 and Enies Lobby adventure.

Triva

 * The special is apparently meant to take place before One Piece Film Z (specifically Glorious Island) as the crew are in their outfits from the start of that movie. Considering Nami's still wearing her dress from the Z's Ambition Arc, it likewise is set some time after that arc.
 * Events that were not canon were animated during the flashback including bits from the Warship Island Arc and the G-8 Arc.
 * Brand New World and Memories were used within the special.