Question: What is the birth name of the character originally voiced by Zack Shada who helps rescue Princess Bubblegum in "Adventure Time"?

Context paragraphs:
Elements (miniseries): Elements is an American animated miniseries based on the show "Adventure Time" by Pendleton Ward.  It aired as part of the show's ninth season on Cartoon Network from April 24 to April 27, 2017.  "Adventure Time" follows the adventures of Finn (voiced by Jeremy Shada), a human boy, and his best friend and adoptive brother Jake (voiced by John DiMaggio), a dog with magical powers to change shape, grow and shrink at will.  In this limited event series, which itself follows the events of the "Islands" miniseries, Finn, Jake, and BMO return home to discover that Ooo has been turned into a veritable dystopia thanks to extreme elemental magic.  Finn and Jake team up with Ice King (voiced by Tom Kenny), Betty (voiced by Felicia Day), and Lumpy Space Princess (voiced by Ward) to set things straight.

List of Adventure Time episodes: "Adventure Time" is an American animated television series created by Pendleton Ward for Cartoon Network.  The series follows the adventures of Finn (voiced by Jeremy Shada), a human boy, and his best friend and adoptive brother Jake (voiced by John DiMaggio), a dog with magical powers to change shape and grow and shrink at will.  Finn and Jake live in the post-apocalyptic Land of Ooo.  Throughout the series, they interact with the show's other main characters: Princess Bubblegum (voiced by Hynden Walch), the sovereign of the Candy Kingdom; the Ice King (voiced by Tom Kenny), a demented but largely misunderstood ice wizard; Marceline the Vampire Queen (voiced by Olivia Olson), a thousand-year-old vampire and rock music enthusiast; Lumpy Space Princess (voiced by Ward), a melodramatic and immature princess made out of "irradiated stardust"; BMO (voiced by Niki Yang), a sentient video game console-shaped robot that lives with Finn and Jake; and Flame Princess (voiced by Jessica DiCicco), a flame elemental and ruler of the Fire Kingdom.  The pilot first aired in 2007, and it was later re-aired on the incubator series "Random!  Cartoons" on Nicktoons Network.  The pilot eventually leaked onto the internet and became a cult hit on YouTube.  After Nickelodeon declined to turn the short into a full-fledged show, Cartoon Network purchased the rights, and "Adventure Time" launched as a series on April 5, 2010.

Adventure Time (pilot): "Adventure Time" is an animated short created by Pendleton Ward, as well as the pilot to the Cartoon Network series of the same name.  The short follows the adventures of Pen (voiced by Zack Shada), a human boy, and his best friend Jake (voiced by John DiMaggio), a dog with magical powers to change shape and grow and shrink at will.  In this episode, Pen and Jake have to rescue Princess Bubblegum (voiced by Paige Moss) from the antagonistic Ice King (voiced by John Kassir).

Princess Bubblegum: Princess Bonnibel Bubblegum of the Candy Kingdom (voiced by Hynden Walch) is a fictional character in the "Adventure Time" animated series on the Cartoon Network.  She is the current incarnation of the Candy Elemental, comparable to the inhabitants of the Candy Kingdom, who are all composed of types of desserts and candies.  In the season 7 episode "Elemental," Princess Bubblegum was revealed to be the current Candy Elemental (in the "Adventure Time" universe, the Elementals are the embodiments of the four main elements that make up the world: ice, fire, candy and slime.  They have existed since the beginning of life, living, dying and reincarnating for eons and millennia).  She rules over the Candy Kingdom, but in the Season 6 episode "Hot Diggity Doom" (the first part of the season's finale), an election was held and she lost to the King of Ooo by a landslide.  As a result, she no longer ruled the Candy Kingdom and the King of Ooo replaced her as the new ruler, until a rebellion against King of Ooo allowed her to reclaim the throne in "The Dark Cloud".  Her proficiency in science and fluency in Korean and German are a testament to her high intelligence.  In 2014, Olivia Olson (the voice actress of Marceline the Vampire Queen) alleged at a book signing that the show's creator Ward had confirmed that Marceline and Princess Bubblegum dated but were unable to put any official confirmation in the show due to controversy.  However, Olsen seemed to redact the statement in a Tweet that same day by stating "I like to make things up at panels.  Ya'll take my stories way too seriously".

Finn the Human: Finn (also known as Finn the Human and born as Finn Mertens) is a fictional character and the main protagonist of the American animated television series "Adventure Time" created by Pendleton Ward.  He is voiced by Jeremy Shada in most appearances.  The character made his debut in the original pilot, where he was named Pen and voiced by Zack Shada, Jeremy's older brother.

Stakes (miniseries): Stakes is an American animated miniseries based on the show "Adventure Time" by Pendleton Ward.  It aired as part of the show's seventh season from November 16, 2015 to November 19, 2015 on Cartoon Network.  "Adventure Time" follows the adventures of Finn (voiced by Jeremy Shada), a human boy, and his best friend and adoptive brother Jake (voiced by John DiMaggio), a dog with magical powers to change shape, grow and shrink at will.  In this limited event series, Princess Bubblegum (voiced by Hynden Walch) removes Marceline the Vampire Queen's (voiced by Olivia Olson) vampiric essence, which unleashes five recently resurrected vampires onto Ooo.  Marceline, Bubblegum, Finn, Jake, and Peppermint Butler (voiced by Steve Little) are forced to deal with the fallout.

Adventure Time: Adventure Time is an American animated television series created by Pendleton Ward for Cartoon Network.  It follows the adventures of a boy named Finn (voiced by Jeremy Shada) and his best friend and adoptive brother Jake (John DiMaggio)— a dog with the magical power to change shape and size at will.  Finn and Jake live in the post-apocalyptic Land of Ooo, where they interact with Princess Bubblegum (Hynden Walch), the Ice King (Tom Kenny), Marceline the Vampire Queen (Olivia Olson), BMO (Niki Yang), and others.  The series is based on a 2007 short produced for Nicktoons and Frederator Studios' animation incubator series "Random!  Cartoons".  After the short became a viral hit on the Internet, Cartoon Network commissioned a full-length series, which previewed on March 11, 2010, and officially premiered on April 5, 2010.

Islands (miniseries): Islands is an American animated miniseries based on the show "Adventure Time" by Pendleton Ward.  It aired as part of the show's eighth season on Cartoon Network from January 30, 2017, to February 2, 2017.  "Adventure Time" follows the adventures of Finn (voiced by Jeremy Shada), a human boy, and his best friend and adoptive brother Jake (voiced by John DiMaggio), a dog with magical powers to change shape, grow and shrink at will.  In this limited event series, Finn, Jake, BMO (voiced by Niki Yang) and Susan Strong (voiced by Jackie Buscarino) leave Ooo and travel across the ocean to solve the mystery of Finn's past.  During their trip, they encounter various creatures, new friends, and a variety of mysterious islands.  The trip culminates with a visit to Founder's Island, where Finn meets his biological mother, Minerva Campbell (voiced by Sharon Horgan), and discovers what happened to the remainder of the human race.

List of Adventure Time characters: The American animated television series "Adventure Time" features a cast of fictional characters created by Pendleton Ward.  The series revolves around the adventures of protagonists Finn (voiced by Jeremy Shada), a 16-year-old human boy, and his best friend Jake (voiced by John DiMaggio), a dog with magical powers to change shape and grow and shrink at will.  Finn and Jake live in the post-apocalyptic Land of Ooo, and travel the land while they adventure.  Along the way, they interact with the other main characters of the show: Princess Bubblegum (voiced by Hynden Walch), the Ice King (voiced by Tom Kenny), and Marceline the Vampire Queen (voiced by Olivia Olson).

Make Out Monday: Make Out Monday is an American pop punk and rock band formed in Los Angeles, California, in 2014.  The band consists of Jeremy Shada, Zack Shada, John Spicer and Seth Renken.  In November 2014, they self-released an EP, "Kicking Cars".  It sprouted three singles namely: Hope Less Romantics, Sirens and Twixter.  A Special Edition version was then released in September 2015.

Supporting paragraphs: Finn the Human Adventure Time (pilot)
Answer: Finn Mertens