Hermaphroditic (3.5e Trait)
From D&D Wiki
You bear both genders.
Prerequisite: You must be part of a race with actual (separate) genders.
Benefit: You can count as either gender for prerequisites and positive effects (such as meeting the prerequisites of a male-only prestige class).
Drawback: You are affected by harmful effects designated to either gender. Also, you always suffer a penalty to disguise when trying to disguise as someone of a specific gender.
Special: You cannot have the Asexual trait.
Roleplaying Ideas: Hermaphrodites are often shunned, most try to hide their "gender" from other members of their race or even of their type. Hermaphrodites in some cultures may be revered, but in others they are killed at birth.