Petra was a Princess, daughter of Queen Mysteria. One day, she went undercover to the city market with her pet spider called Webster to explore and ended up meeting the bard Merry James Watson. Before the two could get acquainted, however, she had to fight the vile Bishop Octopus, who was searching for the Crystal Orb. When Octopus discovered Petra was the Princess, he left the market and kept searching for the Orb.^[1]

After Petra returned to her castle, her mother, who had discovered her departure of that day, forbid her to go the ball that would've occurred that evening. Fortunately for her, her Fairy Gob-Mother Norma, heard her hopeless lament and decided to help her, making a deal with Petra: receiving the powers of a spider, but having to giving up them before midnight or having to give up the possibility of loving someone for her entire life. Petra went to the ball and witnessed her mother, who had the Crystal Orb, attacking the guests, believing them to be assassins from the other kingdoms, who had killed her husband. Petra managed to defeat both Bishop Octopus and Mysteria, now being called the Mysterious Empress, with the help of Merry James Watson, but during the fight midnight came and she reluctantly decided to keep her powers. After the ball, Madame Web came to Earth-423 and recruited the Spinstress for a new adventure.^[1]

• This universe is heavily inspired by the Disney Princess franchise and animated Disney films.^[2]