Piranhas!

[Saintish]

Each should be called a "Starving Piranha", because in real life only piranhas that have been severely underfed bother to eat living tissue.

NERRRRRRDDDDDDDD!
Also, I like what Apartheid suggested. Let the reagent come in tratior poison bottles, like the spider eggs.

That hurt my feelings

I just had another idea: The initially spawned piranhas would still harm people, but not as quickly. It'd be very gradual damage. However, if not fed human flesh for a while, they almost instantly kill+gib/skeletize. This would balance it out.