J.K. Rowling calls a Twitter user an "idiot" for calling 6-time Wimbledon champion, Serena Williams "mannish". However, Serena doesn't seem to care about her bashers as she arrived at the Champions' ball looking like a princess and danced with fellow Wimbledon champ, Novak Djokovic.

On July 11, @diegtristan8 tweeted a photo of Serena Williams' flexing her muscles during her Grand Slam match with Garbine Muguruza on Saturday.

In defense of the 33-year-old female athlete, Rowling replied to his tweet with a picture of Williams on high heels and in a tight red dress, showcasing her womanly curves.

"She is built like a man. Yeah, my husband looks just like this in a dress. You're an idiot," the Harry Potter author tweeted.

Rowling has previously tweeted her support for the American tennis player saying, she's "#TeamSerena" because "you don't meet many super-talented people nicer than she is."

Haters gotta hate, but William's basher kept insulting her "manly arms" with tweets from friends coming in to take his side. Further insults prompted the best-selling author to stop dealing with what he had to say and blocked him.

"Btw if jk rowling is so fierce and amazing why post one tweet block me and then hide, doesn't sound fierce to me lol," Rob tweeted on.

Serena didn't seem to feel insecure about her body as she graced the Wimbledon Champions Ball at the Guildhall in London on Sunday night.

Wearing a cream dress adorned with jewels, the over-all 21-time Grand Slam holder reportedly looked like a Disney princess, aside from being this year's Wimbledon queen.

Williams then took the stage and joined fellow Wimbledon champion, Novak Djokovic for a Saturday Night Fever dance.

Djovik, who was wearing a black suit and a green-striped tie, just won the Grand Slam match against Roger Federer earlier that day and planned to ask his female counterpart for a dance at the Champions' dinner.

The audience cheered as both Wimbledon 2015 champs celebrate their wins enjoying their dance, ending it with a congratulatory hug.