A few years ago, I remember reading an article about a new species of rats discovered in Antarctica that feed on penguins. The article stated that these creatures live below the ice sheets, have heads several times larger than their bodies to keep them buoyant, swarm in packs like piranhas around diving penguins, have sets of razor-sharp teeth for devouring penguin flesh, and can devour a whole penguin within minutes. Is this a load of bull, or do these creatures actually exist? I got some bug to research them today, and can’t find one shred of evidence to determine if what I read was false or not.
I’m pretty sure this was a hoax, but I have no cite.
Perhaps it was a misidentification of a young leopard seal.
Ahoy, it’s a pack of Antarctic sea rats!
Hoax.
You’re thinking of this, perhaps?
It was an April Fool’s joke in Discover Magazine. The story came complete with a small photo of a naked mole rat, modified to make it look as though the rat had a bony plate in its head, which it allegedly used to focus body heat and melt through ice so as to nab the unsuspecting penguin from below.
Every year in the April issue they plant a story up front, in the R&D section usually. Unfortunately they don’t archive those short pieces online, but if I remember correctly it was published around 1994 or 1995.
That’s the article alright, thank you.
How about that? I may be the only one on earth both a.) remembers that drivel and b.) bought it hook, line and sinker. That’s pretty funny, actually.
D’oh! Board hamsters ran too slow and Ringo beat me to it. 
Yup, that was it.
Discover doesn’t do those spoofs anymore. I loved 'em, wish they start again.
Sadly enough my mother fell for the joke for years, as did I since I was rather small and didn’t figure out the concept of an April Fools joke before April Fools day. Took me a few years, but she reminded me, and it was online in their archives at the time (maybe 3-4 years ago?), in an April Fools section, printed also all of the April Fools letters they got in return, and now it is a family joke she will never live down. =)
Ah, here is the article at Discover: http://discover.com/science_news/fool/fool95.html