Don't we have an intelligent, speaking Creeper wandering around? Y'know, the creatures whose sole purpose is to explode and kill you?

It really comes down to definitions. If you define Shroob as 'looks like a Shroob and was claimed to be one', you have no problems. If you define it as 'kills, destroys, and consumes, and that's it', then of course you can't make an agent out of them - you've just defined them to be impossible!

But GLaDOS is incapable of thinking of anything but herself, yet Evie is a viable agent. Maglor is incapable of not being obsessed with the Silmarils, yet Dafydd somehow works. The history of the PPC is full of characters who ought to be psychotically evil - we have an illithid! - but due to various reasons... aren't.

hS

(PS: That said, it'd be a terrible idea, because if your description is accurate, anything worth writing about Agent Shroob would be from the badfic, not from her species. So there's that.)

So if you say it is not possible, then that seems clear it is not. From a theoretical stand point, I see no reason why it is truly impossible. Of course that comes from the idea, that I think when you are writing nothing is impossible. Whether or not it will work, is a different question all together.

I still do not think it would be impossible, merely impracticable. If someone were familiar enough, I think it could theoretically be done.

For the Sith example I was playing around with, this is what I came up with. Sith seek power, Sues appear to have universe altering abilities, this kind of power would be incredibly appealing to a Sith. Further as to working with others, if the partner were to be framed as a tool or slave even, then the Sith would be willing to work with them, provided it furthered the Sith's interest, acquiring the power of the Sues. Then you have a partner agent that can contend with the physical attributes for when the Sith goes off to, well be a Sith, so that he can be redirected. Of course this is entirely academic since I scrapped that entire pairing, because I frankly did not enjoy writing it.

The bottom line is, I think it is possible, just it would take a very intricate knowledge of at least one continuum and possibly another. I was thinking something along the lines of A Sidonian Blood Nematode. Of course it would require work to be a viable method, and it would become something different.