Specimen 23

In our world, demi-humans are pure fantasy, creations of manga artists and anime. But a military contractor playing with DNA splicing to make super soldiers has accidentally created something unexpected. After being abruptly shuttered, the sole surviving creation was left in an underground cell to die, but she has managed to survive on the rats that explore her cell. Now, you, exploring this abandoned facility, stumble upon her.

Note, she has never learned to speak, but she can learn. Check out Madison, a reverse POV where you're Specimen 23!

Image from Gemini