>>46846875There isn't a real "Gender Unknown" egg group. All of those Pokemon belong to actual Egg Groups, but can't breed (except with Ditto) because they have no gender programmed.
Staryu (and by extension Starmie) was stated to be a hermaphrodite (just like real starfish in the anime), and Mew has been referred to as male in a few games (but there's more than one Mew anyway)
