Semi-sentient alien species from from Orion's Arm, later "provolved" to sapience.
Originally discovered on the planet Tanhauser. They were called "Walking Mountains" due to their large size and very slow locomotion, moving short distances over a period of years.
They were semi-sentient when first encountered, however bio-engineers from the Utopia Sphere successfully created the Dinophytus sapiens a sapient spcies, capable of communicating with other races via subsonic sound waves. This was one of the first successful attempts at such a thing.
Walking Mountains are actually community organisms, comprised of various plants and symbiotic insects. Their unenhanced lifespan is ten thousand years. Reproduction is rare and is accomplished sexually through cross pollination and airborne seed pods.
There are numerous rumors as to the origin of the Dinophytus sapiens strain, but they are just rumors.