Okay, I'm a level 15 Warrior going around in the Catacombs fighting around of course. But, I find myself suddenly surrounded by Mud Man after Mud Man, seemingly appearing before my eyes! They just come up in random spots before I can react and it's infuriating fighting them in a group because they will knock your health down to nothing in seconds.
I run from them, more suddenly appear in front of my character and I can't react in time. I'm killed in seconds and it gets worse when other enemies are nearby joining in on the slaughter.
It's like they have a stack of Teleport scrolls by the infinite. They're also always escorted by a Blue-Red looking Mud Man meshed together.