Hufflepuff

The Hufflepuff house was one of the four original houses of the school, founded by Helga Hufflepuff, for whom it is named. If Hufflepuffs were matched to an elemental system, they most closely resemble Earth elementals (Taurus, Capricorn, and Virgo) in their manner and attributes. Their mascot is the badger(*), a very down-to-earth animal who goes about his daily tasks unruffled by any chaos around him. Hufflepuffs are sincere and straightforeward and not afriad of honest hard work. While Hufflepuff rarely produces showy, famous wizards, its graduates are careful and paitent in their work and rarely fail to get the job done.

The current Hufflepuff Head is Professor Sprout and their prefect is Cedric Diggory, who is also their seeker. The house ghost is The Fat Friar.
House members include:
Hannah Abbott, Susan Bones, Eleanor Branstone, Owen Cauldwell, Michael Corner, S. Fawcett, Justin Finch-Fletchley, Megan Jones, Mitchell Lock, Ernie MacMillan, Laura Madley, Eloise Midgen, Alisen Rasener, Kevin Whitby

Their house colors are yellow and black. Their coat of arms is a badger standing rampant on a field divided in quarters of yellow and black. Their Quidditch robes are a bright canary yellow. The entrance to their dorms and common area are somewhere down a corridor off the main entry hall.

(*) I have heard from a decently reliable source that "hufflepuff" or "huflepuf" was an archaic english nickname for "badger" in reference to the whuffling, chuffling noises the animal frequently makes. I've been unable to verify this of late, however, because every web-search just returns hits for Harry Potter sites. Interesting if it's true, but take it with a grain of salt.

http://www.i2k.com/~svderark/lexicon/hufflepuff.html
http://www.harrypotterfans.net/hogwarts/commons/hufflepuff/
http://www.nasubionna.net/hp/hufflepuff.html
http://www.hogwarts.esmartweb.com/hufflepuff.htm