Rini Mini Sailor Moon

Chibiusa is described as a precocious brat who likes pulling pranks. She is the daughter of Usagi Tsukino and Mamoru Chiba. Her real name is the same as her mother's, but is called Chibiusa in Japanese (and Rini in English) to avoid confusion between the two. Her name in the English-language version of Sailor Moon, Rini, is a diminutive of "Serena", the name of her mother. She is known for having pink hair put into a unique style that resembles rabbit ears on top of her head. Chibiusa's hair is apparently truly pink, and not just colored that way for stylistic purposes; its color is stated in the manga's first Picture Diary and in the poem about her in the Sailor Stars CD single.
In Act 20 of the manga, it's mentioned that she is 900 years old, her youthful appearance attributed to the fact that she suddenly stopped growing when she was five. The reason for this is never fully understood, but she begins to age after she becomes Sailor Chibi Moon. By the time of the Dream story arc, she claims to be 902. Her exact age was not disclosed in the anime, and her time traveling complicates guessing. The candles on a birthday cake in one memory indicate that she is about five years old when first introduced, and she seems to be about eleven or twelve when she returns later on. Exposure to the Silver Crystal renders all of Crystal Tokyo's inhabitants functionally immortal.