Gwarhar Lagoon resident
From the Super Mario Wiki
Gwarhar Lagoon residents are fish-like creatures that wear bathing suits and reside in Gwarhar Lagoon in Mario & Luigi: Superstar Saga. They are quite gossipy and will talk to each other about events in the Lagoon.
When the Beanstar breaks into four pieces, Mario and Luigi head to Gwarhar Lagoon. They are soon interrupted by three Gwarhar Lagoon residents, gossiping about Hermie III's Beanstar Piece before going to check it out. Hermie, with some help from the three Gwarhar Lagoon residents, manages to decorate his shell with the Beanstar's Piece, making it a Christmas tree. When Mario and Luigi arrive, Hermie refuses to give up the Beanstar; but a problem arises when the residents start to pay more attention to the Mario Bros., who they recognize, than his prized decorations. Hermie battles the Bros., but is defeated. The residents apologize on his behalf before giving them the Beanstar Piece and showing the Bros. a shortcut out of the area.
In the Minion Quest mode of Mario & Luigi: Superstar Saga + Bowser's Minions, the three recurring residents gossip about and later participate in Wendy's "Cutie Battle Contest," where they form a team known as "The Insane Sisters" alongside two Oho Jees. However, it isn't made clear whether they are actually sisters or not.