There's a number of femboys in nature. I think it's cuttlefish or something similar that can camouflage, turning one side of its body to have female coloring, and the other to have male coloring. It presents the female side to the larger male, and the male side to the female. The fact that this works indicates a high level of intelligence, as deception is difficult for any animal to pull off.

[–] Catoblepas@lemmy.blahaj.zone 24 points 11 months ago* (last edited 11 months ago)

Also ruffs (a kind of shore bird). They form groups so males can fight for mating rights, and for a long time scientists thought the female-mimics looked like females so they can sneakily mate. But it turns out that all the other birds probably know they’re male because females are more likely to join a group that has a female-mimic!

Femboys are just sexy, nature agrees.