Builder (species)
From Tardis Wiki, the free Doctor Who reference
The Builders were a species that resembled eight-inch slugs. They communicated through sophisticated pheromone secretions. The Builders could select their offspring's genetic characteristics intuitively as they gestated them. They became birds that spit acid and were actually sentries, insects that were repair drones, fungal trees and giant flying beetles that could fire streams of volatile gasses. (PROSE: Primitives)
