Brainmos

The Brainmos was a sentient lifeform from the planet Ep, resembling a large yellow sponge. The Daleks' plans to invade Ep led to a model of a Brainmos once being present in one Dalek flying saucers alongside other depictions of lifeforms whose planets the Skarosian tyrants were planning to invade. (PROSE: Inside a Skaro Saucer)