Iceburg

A crap so large that a portion of it juts out of the water, with most of it being below the surface, like an iceburg.

After the all-you-can-eat ribs night, I sat down and dropped an iceburg. It was so sizeable that I had to flush twice!

Double Parked

When you take a crap on top of someone else's unflushed dump.

"I had to go really bad, but the shitter was plugged with someone's turd. So I just double parked it."