Miss Merry Christmas is a Baroque Works agent paired with Mr. 4. She is a stout, middle-aged woman with red hair and wears a necktie that looks like a Christmas tree, matching her codename. Her other notable attire includes large purple-lensed sunglasses, a basket strapped to her back, and sandals. Unlike her slow-speaking partner, Miss Merry Christmas talks very quickly, often pronouncing only the first syllable of words in a high-pitched, child-like voice.
She possesses the power of the Mogu Mogu no Mi (モグモグの実), also known as the "Diggy Diggy Fruit" in English versions. This Zoan-type Devil Fruit allows her to transform into a giant mole or a mole-human hybrid, which Usopp mistakenly identifies as a penguin. Thanks to this ability, she can easily burrow underground in the sands of Arabasta and surprise her opponents, attacking them with her sharp digging claws.
Source: One Piece Wiki
