Star Trek: 10 Strangest Alien Species
8. Tholians
Tholians have been around almost as long as there's been Star Trek. The species primarily showed up in The Original Series and Enterprise, with only anecdotal mentions in other series. That being said, they remain one of the oddest species any starship crew could possibly run into.
As a general rule, Tholians seem to be approximately the same height as an average human, though that's where the similarities end. Tholians come in various shades of red on a strong carapace with six legs. Their "shells" were made of some sort of mineral, and were translucent enough to show what looked like some kind of fluid inside. While they weren't really insects, they were insect-like.
What made them odd to deal with was the lack of what one might describe as a traditional face. Instead, they had two glowing spots on their heads that would turn towards whoever they were talking to, using a language that only consisted of clicks and chirps. If that's not enough, the entire species was hermaphroditic, meaning they all had both male and female genitalia.