Dr. Maxis had a daughter named Samantha Maxis. She was born in what most people believe is Verruckt (a insane asylum in Berlin. If you crawl to the cages I think in the beginning at Verruckt you can hear a woman and child cry)
Samantha's mother died most probably after the birth since Dr. Maxis was a alone father to her.
So one day he gave her a german shepherd. She named it Fluffy. Maxis told her she had to feed Fluffy everyday, walk her and be very careful when playing since she was going to have puppies. Samntha asked if she could keep the puppies to having Maxis responding "We'll see Samantha. One step at a time."
Samantha was also given a monkey by Richtofen to not feel lonely.
She was very fond of Teddy bears too.