Troll reproduction

In the New Planet, New Life universe, trolls are capable of natural reproduction, and actually never lost the ability to do so.

(Note: Much of this was inspired by schim's work.)

History
As trolls evolved into a brutal species following the rise of Her Imperious Condescension, anything seen as "domestic," including reproduction, was frowned upon and expunged from society.

Biology
Trolls are essentially hermaphroditic. Each troll possesses both a bone bulge (similar to a human penis) and a nook (similar to a human vagina). Most trolls choose to prescribe to humanity's ideas of gender norms, and secondary sexual characteristics develop as such. Likewise, if a troll's gender identity changes, their secondary sexual traits will change accordingly as well.