Trell (Mother Tongue)
From Tardis Wiki, the free Doctor Who reference
A trell was an anemone-like species who hid the planet Nateus from the universe. They vibrated with the quantum energy to do this. They rescued Leela from the vortex. If they stopped moving, they disconnected from the vortex, making the planet visible. They had sap-like blood. They were integral to the ecology of the planet. They were able to commune with certain people including visitors to the planet. (AUDIO: Mother Tongue)