胖胖 is the reduplicative form of the adjective 胖 (pàng, 'fat/plump'). Reduplication softens the tone and adds a cute, affectionate feel — like saying 'chubby' instead of 'fat.' It's often used in casual speech to describe people, children, or animals. Note: the pinyin in the source data is written as pán, but the correct reading is pàng pàng; this row likely contains an error.