Question: What RuPaul's Drag Race judge has also appeared on Sing It!

Context paragraphs:
Todrick Hall: Todrick Hall (born April 4, 1985 in Plainview, Texas) is an American rapper, singer, actor, dancer, director, choreographer, and YouTuber.  He rose to prominence on the ninth season of "American Idol," where he made it to the semi-finals.  Since then, Hall has become notable as a Broadway veteran, YouTube star, and judge on "RuPaul's Drag Race".

Carmen Carrera: Carmen Roman (born Christopher Roman; April 13, 1985), better known by her stage name Carmen Carrera, is an American reality television personality, model, burlesque performer, and actress, known for appearing on the third season of the Logo reality television series "RuPaul's Drag Race", as well as its spin-off series "RuPaul's Drag U".  Although she presented as male during the third season of "RuPaul's Drag Race", on May 1, 2012, ABC News reported that Carrera is a transgender woman.

List of RuPaul's Drag Race contestants: This is a list of contestants who have appeared on the American television show "RuPaul's Drag Race".  Contestants compete against each other and are progressively eliminated, until just a winner remains, who is crowned "next drag superstar".  They are judged by drag queen RuPaul and her panel of judges.  The series first aired in 2009 and as of 2017, there have been nine seasons of the show.  A total of 113 different participants have been selected as finalists in the show in its eight years running, with nine drag queens — BeBe Zahara Benet, Tyra Sanchez, Raja, Sharon Needles, Jinkx Monsoon, Bianca Del Rio, Violet Chachki, Bob the Drag Queen, and Sasha Velour being crowned so far as "America's Next Drag Superstar".  In addition, an season aired in 2012 featuring twelve returning contestants from the first four seasons, each competing for a place in the "Drag Race Hall of Fame".  The season was won by Chad Michaels, previously a runner-up in season four.  In 2015, it was announced "All Stars" had been renewed and a premiered on August 25, 2016.  The second season was won by Alaska, who was previously a runner-up in season 5.

RuPaul's Drag Race: RuPaul's Drag Race is an American reality competition television series produced by World of Wonder for Logo TV and, beginning with the ninth season, VH1.  The show documents RuPaul in the search for "America's next drag superstar."  RuPaul plays the role of host, mentor, and head judge for this series, as contestants are given different challenges each week.  "RuPaul's Drag Race" employs a panel of judges, including RuPaul, Michelle Visage, Ross Mathews, Carson Kressley, and a host of other guest judges, who critique contestants' progress throughout the competition.  The title of the show is a play on drag queen and drag racing, and the title sequence and song "Drag Race" both have a drag-racing theme.

RuPaul's Drag Race (season 1): The first season of "RuPaul's Drag Race", later referred to as "The Lost Season", premiered in the United States on February 2, 2009, on VH-1.  Nine contestants were selected to compete in the running of becoming "America's Next Drag Superstar."  The first season was filmed during the summer of 2008.  The winner of the first season won a lifetime supply of MAC Cosmetics, was featured in an LA Eyeworks campaign, joined the Logo Drag Race tour, and won a cash prize of $20,000.  One of the nine contestants to compete on "RuPaul's Drag Race" was determined by an audience vote via the show's official website.  The results were announced in early September 2008.  The theme song playing during the runway every episode was "Cover Girl" from RuPaul's album "Champion".  This season and season one of All-Stars are the only seasons to not feature the "Snatch Game."

RuPaul's Drag Race: All Stars: RuPaul's Drag Race All Stars is an American reality competition television series produced by World of Wonder for Logo TV.  The show is a spin-off of "RuPaul's Drag Race" where RuPaul allows past contestants to come back and compete for a spot in the Drag Race Hall of Fame.  RuPaul plays the roles of host, mentor, and source of inspiration for this series, as contestants are given different challenges each week.  "RuPaul's Drag Race" employs a panel of judges, including RuPaul, Michelle Visage and a host of other guest judges, who critique contestants' progress throughout the competition.

RuPaul's Drag Race (season 7): The seventh season of RuPaul's Drag Race began airing on March 2, 2015.  Returning judges include RuPaul and Michelle Visage, while the space previously occupied by Santino Rice has been filled by new additions Ross Mathews and Carson Kressley.  Matthews and Kressley are only both present for the season premiere and will take turns sharing judging responsibilities.  Shawn Morales, a member of the Pit Crew since the third season and Simon Sherry-Wood, a member in the sixth season, do not appear this season and were replaced by Bryce Eilenberg.  Like the previous two seasons of "RuPaul's Drag Race", the season featured 14 contestants competing for the title of "America's Next Drag Superstar", a one-year supply of Anastasia Beverly Hills cosmetics and a cash prize of 100,000 dollars.  The premiere of season, the show debuted with a live and same-day viewership of 350,000, a 20% increase from the previous season.  On March 20, 2015, it was announced that LogoTV had given the series an early renewal for an eighth season.

Sing It!: Sing It!  is an American situation comedy web series created by Benny Fine and Rafi Fine.  It is executive produced by Benny Fine, Rafi Fine, Max Benator, Todd Lieberman, David Hoberman, Laurie Zaks, Barry Safchik, and Michael Platt, and produced by Mandeville Films, Potvin Sucks Productions, and Fine Brothers Entertainment.  The pilot had a premiere on April 21, 2016, during the Tribeca Film Festival.  The show debuted on May 25, 2016 on YouTube Red, a paid service of streaming original series and movies, similar to Netflix.  It stars Mircea Monroe, Mark Sullivan, Debby Ryan, Preston Jones, Alex Désert, Todrick Hall, Missi Pyle and Ace Young.  It received a 6.1 by 68 user reviews on IMDb.

List of RuPaul's Drag Race episodes: "RuPaul's Drag Race" is an American reality competition television series produced by World of Wonder for Logo TV.  The show documents RuPaul in his search for "America's next drag superstar."  Queen RuPaul plays the roles of host, mentor, and source of inspiration for this series, as contestants are given different challenges each week.  "RuPaul's Drag Race" employs a panel of judges, including RuPaul, Michelle Visage and a host of other guest judges, who critique contestants' progress throughout the competition.  The title of the show is a play on drag queen and drag racing, and the title sequence and song "Drag Race" both have a drag-racing theme.

RuPaul's Drag U: RuPaul's Drag U (as in "Drag University") is an American reality television series that debuted July 19, 2010, on Logo TV.  Its final episode aired in August 2012.  It was hosted by RuPaul and a team of drag queen "professors".  "Drag U" was a spin-off of "RuPaul's Drag Race".  RuPaul confirmed on May 8, 2013 via Twitter that the series had been cancelled.

Supporting paragraphs: Sing It! Todrick Hall
Answer: Todrick Hall