Nickelodeon will debut “ReactToThat,” a half-hour series from top YouTube personalities The Fine Bros., on Monday, Dec. 15.

The 13-episode series is based on Benny and Rafi Fine’s popular YouTube show “React,” in which people are shown literally reacting to a viral video. Nick’s “ReactToThat,” produced in partnership with Nick Cannon and his production company, Ncredible Entertainment, will feature celebrities and kids reacting to web videos and also participating in showdowns where they take on a challenge based on a video they just watched (like making a basketball trick shot or trying to set the world record for fastest clapping).

“ReactToThat” will regularly air Monday through Friday at 6 p.m. ET/PT through Jan. 1, 2015, on Nickelodeon. The kids’ cabler officially greenlit the show in April.

The premiere episode features YouTube stars Bethany Mota, Lia Marie Johnson (of AwesomenessTV) and Paris Smith (“Every Which Way”), plus the stars of Nickelodeon’s “Nicky, Ricky, Dicky & Dawn,” Mace Coronel and Aidan Gallagher.

It’s not Nick’s first YouTube-to-TV series. The Viacom-owned cable net last year aired a half-hour sketch comedy show last year from DreamWorks Animation’s AwesomenessTV and has developed several TV and movie projects with Lucas Cruikshank (creator of the whiny “Fred” character). Nickelodeon also ordered a TV movie based on AwesomenessTV’s “Terry the Tomboy” character played by Lia Marie Johnson.

The Fine Bros. — who have more than 10 million subscribers for their main YouTube channel — launched the “React” series three years ago, and have since generated more than 1 billion video views. This summer, the duo launched a dedicated “React” channel, which now has 2.7 million subs.

“ReactToThat” is executive produced by Nick Cannon, Michael Goldman, Benny Fine, Rafi Fine, Scott Tomlinson and Max Benator, who is The Fine Bros.’ manager and producing partner.

Separately, Fine Bros. Entertainment last week announced that it is producing an untitled feature-length teen comedy in association with Big Block Entertainment Group.