A Mormon Klump is very similar to a cleveland steamer, but involves more than two individuals. It can involve two individuals, but this is more commonly known as a "Sherman Klump". If you stumble upon a situation involving 3 or more people and their poop, it is most likely a Mormon Klump.
The primary receiver of the klumping is refered to as "Sherman", during both the Sherman and Mormon Klumps.
Todd: "Hey man, did you go to that church service last night?"
Henry: "I sure did, but it turned into a Mormon Klump. I had to get out of there".
Todd: "Was Meg the Sherman?"
Henry: "Meg's ALWAYS the Sherman..."