He is a fairly average student in the Ponyville Schoolhouse.
One day, however, Billy is visited by the spirit of Star Swirl the Bearded, who gives Billy the gift of turning into a male Alicorn superhero named Marvel Pony.
When Billy Batponyson speaks out the words "Star Swirlzam!", he transforms into Marvel Pony and joins the ranks of the Alicorns.
Marvel Pony has the power of flight like pegasi, and can shoot bolts of lightning from the same type of horn unicorns possess. He also has superhuman physical strength, being even stronger than Bulk Biceps.
There are limitations to Marvel Pony's superpowers. Billy Batponyson can only transform into Marvel Pony once every 24 hours, and after one hour as Marvel Pony he automatically turns back into Billy.
His cutie marks: as Billy his cutie mark is that of a rising sun and as Marvel Pony is cutie mark is composed of two lightning bolts.
He is supervised very carefully by the Mane Six under the leadership of Princess Twilight Sparkle.