Question: Which character created by Brian K. Vaughan and Adrian Alphona has control of a vehicle in the form of a large frog?

<P0-S0> Chase Stein (also known as Talkback), is a fictional character, a superhero in the Marvel Comics "Runaways". <P0-S1>  1 #1 with most of the other main characters. <P0-S2>  Like every member of the original Runaways, he is the son of evil villains with special abilities; in Chase's case, mad scientists. <P0-S3>  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. <P0-S4>  He was created by author Brian K. Vaughan & artist Adrian Alphona, and debuted in "Runaways" vol. <P0-S5>  However, despite his rule-breaking persona, Chase is fiercely loyal to his friends and remains a valued member of the team. <P0-S6>  Chase is the eldest of the Runaways at age 18. <P0-S7>  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. <SEP> <P1-S0> The Leapfrog is a fictional vehicle appearing in American comic books published by Marvel Comics. <P1-S1>  The Leapfrog is the personal mode of transport for the superhero team Runaways. <P1-S2>  The ship takes on the form of a large frog. <P1-S3>  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. <P1-S4>  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. <P1-S5>  The Leapfrog doesn't actually fly; it "jumps" forward to move. <SEP> <P2-S0> Xavin is a fictional superhero in the Marvel Comics "Runaways". <P2-S1>  They are a Super-Skrull in training, created by author Brian K. Vaughan & artist Adrian Alphona, and debuted in "Runaways" vol. <P2-S2>  2 #7. <P2-S3>  Although Alphona was the series' artist at the time, artist Takeshi Miyazawa first drew the character on print. <P2-S4>  Xavin had first appeared to the Runaways, taking on the form of a black male, but changed into a black female just for the sake of Karolina Dean, a lesbian whom they were to marry. <P2-S5>  Xavin is often seen as a male, simply to be "intimidating". <P2-S6>  Xavin, often called "Xav" for short, is known for their obtuse and warlike personality. <P2-S7>  They had originally found it hard to fit in with the Runaways due in part to their constant gender switching and unfamiliarity with Earth values and norms, though through proving their loyalty to the group, found acceptance. <P2-S8>  They are the child of the Skrull Prince De'zean. <SEP> <P3-S0> "Runaways" is an American comic book series created by Brian K. Vaughan and Adrian Alphona for Marvel Comics. <P3-S1>  The series debuted in April 2003. <P3-S2>  It has covered 13 story arcs, and is currently in its fourteenth. <P3-S3>  "Runaways" has frequently been collected in digest-sized books, which led to booming sales. <P3-S4>  Series creator Vaughan wrote the entire first volume and most of the second, which was continued and ended by Joss Whedon. <P3-S5>  Terry Moore, creator of "Strangers in Paradise" currently runs the series.