Tennis player's nickname?

I summed up the nicknames of the top 5 players in the world and my personal favorite players.

Roger Federer: Niu, Niu Niu, FedEx, Lion King, Fei Tianwang, Fei Shen, Mr. Key, Swiss Tianwang, and King Roger; Idiot, stupid cow (for milk powder)

Djokovic: Noelle, Dede, make trouble.

Nadal: Natto, beans.

Murray: Lei Lei.

Ferrer: Steady, sister.

Luo: Benbo, Shao Bo, Pineapple, Juani, juanito.

Wawrinka: Four eggs, tiles.

Roddick: big p, A-Rod, American cannon

Zarenka: Aza, Vika.

Radwanska: Aga, Aji

Sharapova: Sharapova, Martha

Serena: Serena, Vivian.

Stosur: Sammy, Samoud, se se.

Haining: Juju