• Vine star Hayes Grier joins 'Dancing With The Stars' Season 21

Vine star Hayes Grier joins 'Dancing With The Stars' Season 21 (Photo : Hayes Grier/Instagram)

Vine star Hayes Grier is the latest celebrity revealed to be competing on "Dancing With the Stars" Season 21, which will premiere on Sept. 14.

The 15-year-old social media star took to Twitter to announce his participation in the upcoming season of ABC's hit reality dance competition. He will compete against the likes of music legend Chaka Khan, TV chef Paula Deen, jockey Victor Espinoza, former boyband member Nick Carter, and Steve Irwin's daughter Bindi Irwin.

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Grier, who boasts a huge following on social media, broke the news to his Twitter fans on Aug. 27, Thursday. Asking for his fans' support, he also revealed that his first "DWTS" rehearsal was set to take place the same day.

Meanwhile, celebrity couple Alexa Vega and Carlos Pena are rumored to join "DWTS" season 21 cast as well.

According to E! News, the "Spy Kids" actress and her singer husband will be the first married couple to compete against each other in the popular reality dance show. While there is no official confirmation from ABC yet, a source revealed to the site that Vega and Pena are set to be included in the celebrity lineup for the 2015 fall season.

On the other hand, some official "DWTS" Season 21 cast members have shared their thoughts and expectations of the show's upcoming season. In a recent interview with Us Weekly, "Backstreet Boys" singer Carter said he felt excited to join the show.

Yet interestingly, Carter revealed he was not very confident with his dancing skills. But by joining the show, the former teen hearththrob thought of possibly becoming a better dancer. He also added that it will be "a great experience to learn how to ballroom dance."

Bindi, the daughter of the late "Crocodile Hunter" Steve Irwin, stated that she is thrilled to be part of "DWTS" season 21. As a wildlife conservationist who is used to handling crocodiles and other wild animals, Bindi described her upcoming stint as "completely different to anything I have ever done."

Still, the teenage Aussie expressed her enthusiasm in joining the reality dance series. She called the experience "a completely new adventure," adding that she is "ready to fall in love with the music and dance to come."

The full line-up of "DWTS" season 21 cast members will be announced on Sept. 2 on "Good Morning America."