No they are leeches.While I'm not sure I'd be willing to let it go that far, the thought of seeing the village succumb to any kind of darkness that incurs the wrath of the church does scream wonderful memories of that time the Church of Granas from Grandia II sent Selene and its Cathedral Knights to wipe out that one village suspected of harbouring a piece of Valmar, (which it did).
... and I'd totally be all for that kind of bad ending, should you fail to restore light to the region.
Shouldn't the swamp slugs count? They're similar enough.