Abi

Abi is a little girl from Water 7. She sought help from Luffy during the first filler episode after the Enies Lobby events in the anime.

History
Prior to the events when the Aqua Laguna hit Water 7, Abi and her family sought shelter from approaching tidal wave. As usual, they couldn't bring the family Yagara Bull, Aobire, along with them. However upon returning home, it was discovered that Aobire had gone missing. Since then Abi desperately searched for her beloved pet. With her expereincing recurring dreams about Aobire calling out to her, Abi was ever more determined. Three days later, Abi caught sight of Luffy roaming around the streets along with Chopper. Seeing as he and his crew were the ones who saved Iceburg, Abi decided to ask Luffy for help.

With her money that she kept in a Yagara Bull piggy bank, Abi asked Luffy to help her search for Aobire. Luffy accepted and together with Chopper, they began searcing all over Water 7. Despite searching everywhere however, the three couldn't find Aobire, even with help from Robin's Devil Fruit powers. Eventually Abi and company learned from another Yagara Bull, through Chopper, that Aobire was last heard on the night when the Aqua Laguna hit. Just as it seemed hopeless, Luffy luckily found a piece of Aobire's muffler.

Following another piece of the muffler, Abi and her two Straw Hat companions eventually came to the underground passages of that town that was built over by present day Water 7.