The Fall Out Boy frontman announced the happy news on his Instagram on Weekend with a lovely family snap revealing the newborn and exposing the strange moniker.
He composed: “So fired up to create Marvel Jane Wentz. Being so thankful that she’s here… annnnd she’s already ready to takeover [sic] the globe.
The couple, who’ve been collectively since 2011, are also parents to Saint Laszlo, three and Wentz has a nine-year-old son Bronx from his matrimony to Ashlee Simpson.
After the labor and birth, Wentz told PEOPLE: “Were so happy to welcome Marvel Jane Wentz into the world.
“Her brothers are both very worked up about their brand new child sister.”
The pair affirmed they were anticipating a girl on New Year’s Day, with the 38-year-old star having previously joked about having ” a whole lot of testosterone in the house”.