Dren is an attempt to create The Seether.Let's see, she is not born like other girls, she may not look like other girls, and it's pretty clear that she's hard to dispatch ("Can't fight the Seether!")
Dren looks like Mewtwo.She does! Which follows that she might have been an attempt to create a living "Pokemorph". Poor thing. Nobody deserves that kind of life.
Insanity is genetic within Elsa's family.Think about it. Her mother was clearly crazy, Elsa, as Clive noted, is rather fucked up herself, particularly noted when she mutilates Dren, and the fact that she was trying to use a highly unethical and illegal hybrid as a daughter. And well, let's not even get into male Dren.
Dren's human DNA came from Elsa's mom.It was all part of her sick freudian thing. She wanted to have some revenge on her mother, that's shy she remade her as a "lesser" humanoid creature and why she wanted to raise her. On the other hand she did love her mother and/or Dren which was what drove her to act caring at times. She transferred her love/hate for her mother to poor Dren.
It will be a perfectly normal human childElsa's, I mean. By the end of the movie she was pregnant with Clive's perfectly human son, because Dren, as a hybrid, was actually infertile and she/he only inseminated Elsa with Clive's sperm, you know, just like succubi/incubi did in medieval lore.
Elsa is a Farscape fanAnd the naming of Dren was totally passive-aggressive.
Dren was an attempt to create a human-Xenomorph hybrid.It's never really clear what Dren's non-human half is, as it matches no earthly creature. But what if it's something not of this Earth? Both Dren and the Xenomorphs possess stinger-tails, very humanoid anatomy, and Ugly Cute baby forms. Dren's inhuman behavior could be the result of her Xenomorph thought processes conflicting with her more human brain, and her ability to change genders might be the fault of a "conflict" between the human genetic code for there to be a sex and the Xenomorph genetic code to possess no gender.
There's at least one other hybrid out there.Dren turns into a male briefly after having sex with Clive. Why did she take so much longer to change than Ginger? She didn't need her female aspects anymore because she had already reproduced. Dren developed as a fetus very rapidly, and this trait went on to her and Clive's offspring (Okay so it took several days in Dren's case, but her and Clive's child would have wildly different DNA, so who knows). She gave birth to it in the tank briefly before Clive and Elsa found her in deteriorating condition. After everything was over, by the time anybody checked the tank, it had taken off into the woods.
Dren's not deadBecause the last several times they left Dren for dead it was up within the hour. For all we know Dren could have recovered perfectly and is quietly being prepped for the next stage of the experiment himself.
Dren is at least partially modelled after GiegueAt least subconsciously. Elsa could've been a Franchise/MOTHER fan.
Having sexual intercourse causes Clive and Elsa's creations to change sexes.Ginger didn't become male until after she and Fred "bonded" for the first time. Similarly, Dren became a dude soon after having sex with Clive.