If you mean the Campaign called Poison Mushroom, then I suggest using a group of 15 trolls and a Necromancer to defeat the 4 defense rooms in the south. After that spawn 2-4 Bile demons in the Grave Yard wreckage to attack the treasure rooms. Use your guild party with a vampire to destroy the dungeon heart.
It's much easier with a strong immortal. I got a 98% victory on the first attempt with a level 22 Tiny with the 4x button pushed in.
Chaos Theory Join us if you wish to max out your dungeon and challenge your peers. No need for Baby Killing in here!