Haniu is Hanyuu.
Hanyu's Japanese name is はにゅう ゆづる, pronounced hanyu yuzuru (pronounced "hanyu yuzuru"), because the Japanese romanization of hanyu in the name Hanyu Knotts is hanyu, which is similar to the Chinese word "hanyu," and it sounds cute, so he was called Hanyu. It sounds cute, so I called him HANIU.
Hanyu's other nicknames:
Jiuer, because Hanyu's colors were very similar to those of Jiuzhaigou's scenery, fans called him Jiuzhaigou fairy, or Jiu Xian for short, or Jiuer, and that's how he got the nickname.
Yuzu, because Hanyu's English name is Yuzuru Hanyu and his Japanese name is はにゅう ゆづる, and yuzu (ゆづ) means grapefruit in Japanese, so Chinese fans gave him this nickname.