Rodents of Unusual Size, from the 1987 movie, The Princess Bride. They are known to attack in the Fire Swamp.
-After Westley rescues her from the lightning quicksand-

Buttercup: We'll never succeed. We may as well die here.

Westley: No, no. We have already succeeded. I mean, what are the three terrors of the Fire Swamp? One, the flame spurt - no problem. There's a popping sound preceding each; we can avoid that. Two, the lightning sand, which you were clever enough to discover what that looks like, so in the future we can avoid that too.

Buttercup: Westley, what about the R.O.U.S.'s?

Westley: Rodents Of Unusual Size? I don't think they exist.

-Immediately, an R.O.U.S. attacks him-
by Kaarmu June 1, 2007
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Rodents Of Unusual Size. These guys seem t be a higher level Lab Rat in Borderlands.

They also have adapted an unusual power to shoot a type of shock beam with their now goggle'd eyes.
When my friend and I are going through on level 50, we see these futuristic larger rat type enemy. They are called R.O.U.S.; short for Rodents Of Unusual Size
But when we are boosting lower levels with our level 50, we only see Lab Rats.
by EpicAurbis November 6, 2012
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R.O.U.S's are Rodents Of Unusual Size. It comes from the 1980's movie Princes Bride, in the fire swamp scene where Buttercup and Wesley encounter the ROUS's. The rodents are about the size of a large dog.
R.O.U.S are like a Capybara. They are the worlds largest rodent.
by Mina72 August 18, 2011
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