Smosh

Smosh are a YouTube comedy duo consisting of best friends Anthony Padilla and Ian Hecox. They are currently the third most subscribed channel on YouTube with nearly 20 million subscribers, after PewDiePie. Nice Peter has hinted at their appearance many times before, and they finally appeared in Artists vs TMNT.

Information
Smosh was founded by Anthony Padilla in 2002, but it wasn't until 2005 that their YouTube account was created. Early videos on their YouTube channel included lip-syncing famous theme songs, such as Power Rangers, Mortal Kombat and Pokémon, the latter of which became the most viewed video on YouTube at the time. Smosh is also known for its cast of recurring characters, such as Ian's mother Cheryl, That Damn Neighbor, Brad Padilla, and Charlie the Drunk Guinea Pig. They currently have a video game in the works based on their popular Food Battle series. They currently have several channels, like Smosh Games, Smosh 2nd Channel, Shut Up! Cartoons, and ElSmosh. A feature film starring Anthony, Ian, Jenna Marbles, Shane Dawson and other Youtubers titled "The SMOSH Movie", distributed by Lionsgate, is in development.

Anthony Padilla

 * Raphael da Sanzio Urbino

Ian Hecox

 * Michelangelo Buonarroti

Trivia

 * They were the third guest duo to appear in a battle, after Rhett & Link and Key & Peele. However, they were the second after Rhett and Link to battle on the same side.
 * Smosh, along with PewDiePie, Jenna Marbles, and Ray William Johnson, are the only YouTubers to appear in an ERB that have more subscribers than ERB itself.
 * PewDiePie was the only one who appeared as a cameo.
 * Both PewDiePie and Smosh appeared in season finales.
 * Smosh is the only duo to appear in an ERB that has more subcribers than ERB themselves.
 * In an episode of Rhett & Link's podcast, Ear Biscuits, Rhett and Link revealed that they had performed an episode of Epic Rap Battles of History with Smosh. (https://soundcloud.com/earbiscuits/ep-32-smosh-ear-biscuits)
 * Anthony hinted towards Raphael by showing that they were reading a book on him in one of his and his girlfriend's videos on their separate channel, WatchUsLiveAndStuff.
 * Peter once mentioned that he'd like to have Anthony play Ash Ketchum, but only if Ian played Pikachu, and as such, both have been constantly suggested and speculated to play those characters in a future battle.
 * Peter said he wanted them to play Bill and Ted against Lewis and Clark; however, Smosh didn't like the idea.