Giant spiders, maybe. Goremaw Speartails. Other tribes of Onontakha. Tlaxti hives. A flock of slaughter birds, perhaps. These are all the kind of things you expected your troops to find in their little sojourn around the lake.
Not a massive army of the ugliest, most hideous stitched-together walking corpse abominations to ever walk Yoyhen's fair grasses.
As the hunters and braves attempt to circle around the infested area and work out what is going on, it becomes clear that the twisted mind behind these isn't taking itself entirely seriously. There are a few more traditional undead mixed in with the shambling herd of monstrosities, some Kamakuran and Flembic humans calling themselves the Decrypted Paladins. They have similarly hideous names for the non-sentient undead beasts they are approximately directing; the Gangrenous Gentlemen, the Moldering Madams, the Fetid Fools, the Necrotic Noblemen, the Loathsome Ladies, the Cavorting Corpses and the Cadaverous Clowns. Apparently they're patrolling out of a nearby stronghold named Midian, under the orders of a lovely individual known as Malevolence. Figures.
There are over a hundred and fifty of the walking corpse abominations, all told, with eighteen of the other undead. The Nightshades assumed you'd want a report, so they carefully counted them all, whilst the Kitties made a spirited attempt to thin the herd a little. Their hit and run attacks bring down a couple of the ugly brutes.
That was, on reflection, a mistake. Buoyed with overconfidence, your forces pushed their range advantage and their superior agility a little too far. Finding their paths of retreat cut off, well, the survivors aren't sure how the other half of their units died - they were too busy running for their lives to look back.
It was probably grisly and unpleasant, anyway.
Somewhat chastened, the remainder of your troops hurry on to their next target, hoping it will take them out of the range of these surprisingly deadly creatures. They leave six of Nightshades' braves, four Fitty Kitties and three Hitty Kitties lost behind them. Going back for the bodies is not high on their list of priorities.
Some idiot - Sarlis Foxglove, the Decrypted Paladins inform you - sends their Tritoni and Onontakhan archers straight into your massive patrol of undead, just down the lake from Midian.
Unfortunately the bastards are quick and over half of them somehow manage to get away. To add insult to injury, they actually manage to take down three of the Fetid Fools with hit and run attacks while they're at it.
Four Onontakhan braves and thirteen Tritoni hunters got away from your patrol; the bodies of their thirteen compatriots are not much of a compensation, especially as they haven't even had the decency to rise up and replace your lost walking corpse monstrosities.