A person who identifies as androgyne has a gender that is either both masculine and feminine or between masculine and feminine.
Bigender
A person who identifies as bigender has two genders.
People who are bigender often display cultural masculine and feminine roles.
Polygender and pangender
People who identify as polygender or pangender experience and display parts of multiple genders.
But I think Genderfluid is still correct for the last panel in the context of the comic as a whole.
Genderfluid
A person who identifies as genderfluid has a gender identity and presentation that shifts between, or shifts outside of, society’s expectations of gender.