Transmat:Species
The Gelth were a humanoid species who lost their bodies in the Time War. Though they originally had biological bodies, the Gelth were eventually reduced to a gaseous form during the Time War, after their bodies were destroyed during the conflict. They could shape this gas into a wraith-like form, but they needed to be in a gaseous environment to survive
The show's been on forever. Some species names are simply going to get reused. One of the most obvious are the Vogans. Most fans remember the Vogan from season 12's Revenge of the Cybermen. But there's also the [[Vogan (The Vogan Slaves)|Vogans that plagued the Third Doctor… ]]
The top-level category for species is category:species. Obviously, that's hard to grasp, but you'll get there in the end.
If you like alien species that are based on Earth animals, you're in luck. All you have to do is go to the page of an Earth mammal and check out the "looks like" box. For instance, if you wanna know what aliens look like elephants, just go that pachyderm's page and find yourself a breadcrumb at the top of the page.
