Fluffy, the dog that belonged to Samantha, the daughter of Dr. Maxis and is mentioned in Der Riese by two of the radio messages. One radio broadcast hears Dr. Maxis giving Fluffy to Samantha. He tells her that she is pregnant and is expecting puppies soon. Samantha asks if she can keep the puppies too. Dr. Maxis says that they'll see, and that it will be taken "one step at a time." The plan seems to fall to pieces soon afterwards, as Fluffy is secretly experimented on by Edward Richtofen and Maxis (unknown to Samantha). The experiment was to try and teleport an animal instead of a human. But the fatal time is when Samantha walks in to the lab to see her father. Edward Richtofen leaves the room, locking her and Maxis inside, with Fluffy, who has turned into a Hellhound. And because Fluffy was pregnant with puppies, she gave birth to living Hellhounds. a degenerate body does follow though. Shortly following this, the Der Riese facility was overrun by Zombies and Hellhounds.
In the end cutscene of Origins, Fluffy is seen alongside Samantha and Eddie.