Roba is a short older lady who wears red blush and lipstick on her somewhat wrinkly face. She additionally has poofy light tan hair with two curls and a purple bow on each side. She also wears a blue pearl necklace and a black and purple dress with green markings on it.
She's very cowardly, since she has hidden in a chest when a storm hit the boat on which she was traveling. In addition, when the Straw Hat Pirates talk about throwing her out of their ship, she totally panics.
She has a deep sense of honor. While talking about the legendary treasure hidden on Mecha Island, she admitted that she has never seen it, even if she is sure that it exists. She also wants to take the blame for her son's behavior, saying that it's her fault that he is so ambitious and greedy.
She was found by the Straw Hat Pirates at the beginning of the movie closed in a chest. Monkey D. Luffy and his crew accept to bring her back home, in Karakuri Island, with the promise to have in return a legendary treasure hidden on the island.
Despite being Ratchet's mother, she does not approve her son's plans to control the giant sea turtle and conquer the world, and she often tries to make him change his mind, with the only effect of being imprisoned in the castle's dungeon with the Straw Hats.
In the end, after Ratchet was defeated, she spanked him.