In my real life space campaign, Iki Piki is a pachekki, an alien species described in GURPS Aliens. Pachekki are all sex-changers. They go through a cycle of being alternately male and female. But I've never had occasion (or really, desire) to explain that in the comic. So for the purposes of the comic, Iki Piki is basically just male.

In fact, the information on Iki Piki's reproductive biology presented in #464 and #467 is completely different to how the pachekki work. So although he resembles a pachekki, in Irregular Webcomic! canon, he isn't actually a pachekki.