Who is Hayes Grier?

The new season of Dancing with the Stars has gotten underway, and the question everyone is asking is: who the heck is Hayes Grier? If the name doesn't sound familiar, than you're probably not among the millennial generation.

Hayes Grier is an internet sensation with over 3 million followers on Twitter, 4 million subscribers on Vine and over 700,000 on YouTube. Now, he's the youngest male dancer on DWTS at age 15. The youngest ever was Hunger Games star Willow Shields at 14. His partner is Emma Slater.

Grier is best known for his Vine videos, those short 6-second internet videos. It's not uncommon for one of his videos to have over 1.5 million views.

Hayes' brother Nash is also an internet star with over 12 million followers on Vine.

It remains to see if those followers will help keep the internet wunderkind around on more traditional media. However, early reviews seem positive.

Other "celebrities" on the 21st season of Dancing with the Stars include

singer Tammar Braxton, actor Gary Busey, Backstrett Boy Nick Carter, TV chef Paula Deen, jockey Victor Espinoza, singer Andy Grammar, wildlife conservationist and (daughter of the late Steve Irwin) Bindi Irwin, singer Chaka Khan, actress Alexa Penavega (Spy Kids), actor/singer Carlos Penavega (Big Time Rush) - and yes, they are husband and wife - Real Housewives of Atlanta star Kim Zolciak Biermann and international hero Alek Sarlatos.