Breen

The Breen are an extraterrestrial humanoid species native to the ice planet Breen. Their true appearance remains unknown, as they have never been seen onscreen without their refrigeration suits, but the shape of their masks suggests that they have a snout. They are also notable for having no blood or other liquid running inside their bodies. Like the Ferengi, the Breen have a four-lobed brain.

As much as they are a reclusive, rarely seen race, they are also one of the most powerful military forces in the galaxy. Initially neutral, the Breen later joined the Cardassians and the Changelings in the a final war against the Federation.