Anglicism Spotting

Here's a little something that turned up in a vocabulary test last year. I didn't get it then, and for the life of me, I still can't figure it out. What was that student thinking? Anyway, dear 9th graders: If this ever turns up again, you'll know what to write - or will you?

"Ugly bags of mostly water"

Here's one for 9d: The example I used to illustrate the adjective "ugly" in the vocabulary part of our test really wasn't mine - you can read all about the "Star Trek - The Next Generation" episode this statement comes from right here.
Only recently has it come to my attention that there is, in fact, a documentary about the Klingon Language Institute (in Klingon and starring Michael "Worf" Dorn! 8) ) that is also called "Earthlings - Ugly Bags of Mostly Water", although technically it wasn't the Klingons but the Microbrains who first came up with that description. Qapla', nevertheless.