I think that's the "Pink Sunfish" from this page.

Those are the awesomest erasers ever (we call 'em rubbers in England, but, heh, I know that makes you Yanks snigger). I sent the link to the woman at work who orders our stationery and, whilst she agreed wholeheartedly that the presence of these tiny but useful creatures would enhance everyone's workday, she was doubful that she would get approval from the powers that be to order them in vast quantities. And we'd need vast quantities because there's 1,000 staff and if there were't enough to go round, or sufficient variety of creatures to choose from, there'd be fights. Trust me on this.