The Mother of Monsters

One sign pointing to a side room stands out - 'The Mother of Monsters'. You're curious as to what it could be about so you enter the indicated room.

While the main room had a few people milling about in it this room is empty. Most of the room is taken up by a strange pool filled with an inky black liquid, several plaques describing the seemingly missing exhibit.

They talk about a recurring archetype of things that birth seemingly endless monsters, sometimes this 'thing' is a monster itself while others are more human but always described as female. In particular it mentions the name Echidna, a half-snake half-woman that was the mother of countless famous monsters throughout Greek myth.

You look at the pool, wondering where the exhibit is. You could swear you saw the surface of the liquid ripple...