Wikipedia
Femizon may refer to one of two groups owned by Marvel Comics and appearing in their Marvel Universe.
The first group to be called Femizons were the women of Femizonia, a gynarchic future world in an alternate timeline where women had become Amazon-like warriors, ruling over male slaves. It was this world that produced Thundra, a recurring enemy, and later ally, of The Thing.
The second group to be called Femizons was a group of all-female supervillains in the Marvel Comics universe. They were enemies mainly for Captain America, and their goal was to conquer Earth and create a utopia where women ruled. Led by Superia, who claimed to be inspired by stories of Thundra's Femizons, the group consisted of a large number of established female criminals and super villainesses.