Biegel reportedly based Vayntrub’s character on the artwork of Erica Henderson, who drew The Unbeatable Squirrel Girl for Marvel Comics.
Vayntrub voiced Squirrel Girl on Marvel Rising, so she was the obvious choice for the live-action role.
He also shared a few behind-the-scenes images that depict Milana Vayntrub in costume as Squirrel Girl.
Squirrel Girl, also known as Doreen Allene Green, first originated in the Marvel Comics in 1991, and has since then appeared in multiple animated projects, including Ultimate Spider-Man, and various video games.