Hermaphrodite

In biology, a hermaphrodite was an organism that had reproductive organs normally associated with both male and female sexes.

Despite their female-like voices, Alpha Centaurans were hermaphrodites and should properly be referred to as "it". Nevertheless, the Doctor generally used the masculine to refer to the Federation ambassador to Peladon. (DW: The Monster of Peladon)

Chelonians were hermaphrodites and all members could lay eggs. Despite this, Chelonians were referred to as males. (MA: The Crystal Bucephalus)

The Sloathes (NA: Sky Pirates!) and the Brascans (EDA: Kursaal) were also hermaphrodites.

There seemed to be no visual distinction between male or female Ood, which would suggest that they were hermaphrodites. (REF: Doctor Who: The Visual Dictionary) On the other hand, when Donna called an Ood "it", the Doctor corrected her, saying she should call him a "he". (DW: Planet of the Ood)