The secret behind Serena's superhero catsuit at French Open

'I always wanted to be a superhero, and it's kind of my way of being a superhero. I feel like a superhero when I wear it.'

A marvel on the tennis court, new mum Serena Williams is now sporting her own superhero outfit as she makes her return to Grand Slam tennis.

"I call it like my Wakanda-inspired catsuit. It's really fun," the American laughed, referencing the fictional Sub-Saharan African nation which is home to superhero Black Panther in Marvel Comics.

"I feel like a warrior in it, like a warrior princess kind of, queen from Wakanda maybe," she said smiling, following her opening round victory over Kristyna Pliskova at the French Open on Tuesday.

"I'm always living in a fantasy world. I always wanted to be a superhero, and it's kind of my way of being a superhero. I feel like a superhero when I wear it."

Behind the jokes, there is also a more serious reason for the choice of skin-tight bodysuit outfit for the American who only had her daughter last September.

Serena has spoken about health concerns over blood clots in the days after giving birth, and on Tuesday said: "Yeah, the catsuit, I had a lot of problems with my blood clots, and, God, I don't know how many I have had in the past 12 months.

"So it is definitely a little functionality to it. I have been wearing pants in general a lot when I play so I can keep, you know, the blood circulation going.

"It's a fun suit, but it's also functional so I can be able to play without any problems."

Next up for Serena is 17th seed Ashleigh Barty. The Australian would be forgiven for cursing her luck to have landed the most dangerous of floaters -- with or without super powers.