Name: The Pods
AKA: Anything else
Location: Deep Space
Novel: Invasion of the Body Snatchers
Author: Jack Finney
Natural History:
Probably one of the oldest lifeforms in the galaxy, the Pods have perfected survival. As their planet began to die, slowly, over immeasurable time, they too evolved, slowly over immeasurable time. As the planet died, they escaped, fleeing to whatever planet they drifted upon, taking the form of the inhabitants and eventually taking over as the dominant life.
They look like seed pods, but on a giant scale. They grow like normal plants do with those already taken over serving as care takers for the fields of pods that are produced to replace the indigenous population. Those care givers place the pods into towns, hidden places, trunks, and in closets for the non-taken over to be replaced.
The Author and myself were able to see this transformation. The pod is placed in close proximity to the target. Over a short span of time, maybe a night, the pod begins to burst at the sides, a white foamy substance emerges, and the pod bursts open. There is a semi-formed white, blank, life-form inside, slowly developing and taking on the characteristics of the target. Eventually it becomes identical to the target and steals the life force and memories, becoming anything organic. The original is left a lifeless husk and is turned to empty grey matter.
The only difference between the pods and the original: emotion. The replicas cannot emote or share emotion, only the pretense of it, a simulation of emoiton Also, a collective knowledge of where the pods came from, their history, and their purpose. A collective knowledge of everything the pods were and have become. Mars and the moon used to have life, but no longer thanks to the pods. The transformation is painless and generally occurs while the target is asleep. Needless to say, The Author and I did not sleep while around this dangerous parasites. It seems plant-life has evolved to be the predator and us, the prey.
"The pods arrived, drifting onto our planet as they have onto others, and they performed, and are now performing their simple and natural function - which is to survive on this planet. And they do so by exercising their evolved ability to adapt and take over and duplicate cell for cell, the life this planet is suited for."