|Relations||Helen (adoptive sister)|
|Species||Human, unknown alien race|
|Hair Color||Black and White|
|Portrayed By:||Mark Wylie|
|Gallery | Quotes | Appearances | Merchandise|
Pierce is another rouge Plumber's kid that appears in Ben 10: Alien Force. It seems that Pierce is a half porcupine alien and half human. He worked with a Tetramand-human hybrid named Manny and a Kinceleran-human hybrid who is also his little sister, Helen, to capture aliens.
He worked with Manny and Helen prior to "Plumber's Helpers", trapping what they thought were dangerous aliens out to conquer Earth. Unlike Manny and Helen, however, after sending a kid with a Plumber Badge to the Null Void he began to have doubts about what they were doing. However, before he could voice his concerns, he was believed to have been killed when an attempt to destroy a DNAlien went wrong. Though, Pierce was actually tapped in the Null Void and began working with Max Tennyson to protect its inhabitants from D'Void, gathering other Plumbers' kids who were trapped there.
He also appeared in "War of the Worlds: Part 1" helping against the alien threat and when the battle is over he becomes a pupil of Grandpa Max.