Star Trek: 10 Strangest Alien Species
3. Tardigrade
In the real world, tardigrades are eight-legged micro animals that live in water and have been found in almost any conceivable environment on Earth and beyond. They were the first terrestrial animal to survive being exposed to space, which probably makes the families of the tardigrades that crashed on the Moon in 2019 relatively happy.
On Discovery, the tardigrades encountered in season one were much bigger and far more dangerous.
This massive species was not a tardigrade but was given the name because of its resemblance to the micro animal. These tardigrades were far more complex, possibly even sentient. The Discovery accidentally stumbled across one on a Klingon ship. It had killed virtually everyone on board, and had proven itself strong enough to potentially tear through the hull.
What really set it apart was that it was a multi-dimensional creature that could travel through the mycelial network the Discovery was trying to navigate, with a lot of difficulty at that point. They were able to use the tardigrade as a biological navigation computer for a time, until other means were found.