Easily one of the best character concept in this universe; the idea of a sweet tooth, witch-like mother with the ability to give life at many levels (both her biological children and her homies) is very congruent —especially considering the potential reference to Ukemochi, a goddess addressed as both creator of food and sustainer of abundance and life.
Really good design, perfectly evoking what it intends to yet adding smart details like Napoleon's hat-guard and the reference to Aesop through the image of a sun and a cloud together and casting storms.
The Soru Soru is one of the most interesting devil fruits.
The cannibalistic twist during her flashback is one of Oda's best.
When done well, achieves a great balance between goofy and terrifying.
And personally I found both her and her context (territory, crew, etc.) very entertaining to know. Lots of fairy tale references and creative aesthetics and concepts. Oda put a lot of work behind the Big Mom Pirates and Totto Land.