Black Goo

It sounds like a term a little kid would make up- like Calvin's Gooey Kablooie.

I understand it is Chemical A0-3959X.91 – 15 but still.....

not a fan of that name. Like you said, sounds childish. Too generic and vague. Surely a better name? Evojizz?  

Mucous

IRaptus Your appearance has changed.

DV Not bad at all.

I don't know what I would call it but Black Goo sounds stupid to me. I cannot imagine David saying 'this is black goo'.

Life-agra

I don't like the term either, it sounds like something from the Turtles universe.