Pepe!

With apologies to Splintered Light...

The deeper levels of Castle Meatgrinder are populated by the slimiest critters in the dungeon.  Oozes, slugs, and all sorts of wet nasties - you can't get slimier than actual slimes, after all.  Naturally, these fellows are perfectly at home in the dank corners of the dungeon.

Rumor has it that these particular dungeon denizens have a particular hatred for moneylenders and female adventurers, but some say those are bedtimes stories designed to scare the gullible.

Whatever the truth about these particular monsters, they are very rare.  

As mentioned above, you can get this 13 toadman warband from Splintered Light for just $10 USD.  They have a ton of character, are quick to paint, and provide some variety to a dungeon beyond the everyday kobold/goblin/orc/ogre progression.  While they don't look much tougher than your standard orc warband, what with the lack of armor and cheap spears, I'm planning on building some pools and ponds that they can use for easy movement and ambuscades.  Fights with surprise attackers with little staying power make for a different sort of encounter than stand-up fights against armored hog faces.  These surprising chaps should keep the players on their toes, and give them a healthy respect for any pools and wells they encounter.