question: Which character created by Brian K. Vaughan and Adrian Alphona has control of a vehicle in the form of a large frog?
answer: Chase Stein
context: Title: Chase Stein
  Passage: Chase Stein (also known as Talkback), is a fictional character, a superhero in the Marvel Comics "Runaways".  He was created by author Brian K. Vaughan & artist Adrian Alphona, and debuted in "Runaways" vol.  1 #1 with most of the other main characters.  Like every member of the original Runaways, he is the son of evil villains with special abilities; in Chase's case, mad scientists.  Chase is often regarded as the "wild card" in the series, due to his often changing role in the group, from being the getaway guy and technical guru to the "loose cannon" after he departed the group for a short while.  However, despite his rule-breaking persona, Chase is fiercely loyal to his friends and remains a valued member of the team.  Chase is the eldest of the Runaways at age 18.  Chase shares a psychic and empathic link with deinonychus Old Lace, granting him the ability to command the dinosaur to do his bidding and also possesses the Fistigons, the world's most powerful gauntlets.
  Title: List of Runaways story arcs
  Passage: "Runaways" is an American comic book series created by Brian K. Vaughan and Adrian Alphona for Marvel Comics.  The series debuted in April 2003.  It has covered 13 story arcs, and is currently in its fourteenth.  "Runaways" has frequently been collected in digest-sized books, which led to booming sales.  Series creator Vaughan wrote the entire first volume and most of the second, which was continued and ended by Joss Whedon.  Terry Moore, creator of "Strangers in Paradise" currently runs the series.
  Title: Leapfrog (comics)
  Passage: The Leapfrog is a fictional vehicle appearing in American comic books published by Marvel Comics.  The Leapfrog is the personal mode of transport for the superhero team Runaways.  The ship takes on the form of a large frog.  Originally created by Janet Stein and Victor Stein, the Leapfrog was used by the Pride when they had to perform their Rite of Thunder for the Gibborim.  After the Pride was destroyed by the Gibborim, control of the Leapfrog rested with Chase Stein and has since been used as the primary mode of transportation for the Runaways.  The Leapfrog doesn't actually fly; it "jumps" forward to move.
  Title: Loners (comics)
  Passage: Loners (originally named Excelsior) is a spin-off mini-series of comic books from Marvel Comics, first appearing in the pages of "Runaways".  It consists of a Los Angeles-based support group for former teenage superheroes from New York, founded by Turbo of the New Warriors, and Phil Urich, the heroic former Green Goblin.  Their goals are initially stated to be to help fellow teenage superheroes to adjust to normal lives while coping with their powers, and to dissuade other superpowered teenagers from becoming heroes, but these goals are discarded in their own miniseries in favor of the group apparently wanting to avoid using their powers for any reason, even if that means abandoning helpless victims of crime to their fate.  Although all the characters were created by different authors and artists, the team itself was created by Brian K. Vaughan and Adrian Alphona, with other characters (Spider-Woman, Hollow, and Red Ronin) added to the cast during the events of the 2007 miniseries.
citations: Leapfrog (comics) Chase Stein