Prisoner Of Azkaban, and I'm going to show you the original then the translated version.
I hope this is ok, I haven't gotten permission from anyone to copy Jk's words, but I'm hoping it is alowed.

Harry went down to breakfast the next morning to find the three Dursleys already sitting around the kitchen table. They were watching a brand-new television, a welcome- home-for- the-summer present for Dudley, who had been complaining loudly about the long walk between the fridge and the television in the living room. Dudley had spent most of the summer in the kitchen, his piggy little eyes fixed on the screen and his five chins wobbling as he ate continually.
Harry sat down between Dudley and Uncle Vernon, a large, beefy man with very little neck and a lot of mustache. Far from wishing Harry a happy birthday, none of the Dursleys made any sign that they had noticed Harry enter the room, but Harry was far too used to this to care. He helped himself to a piece of toast and then looked up at the reporter on the television, who was halfway through a report on an escaped convict:
"... The public is warned that Black is armed and extremely dangerous. A special hotline has been set up, and any sighting of Black should be reported immediately."
"No need to tell us he's no good," snorted Uncle Vernon, staring over the top of his newspaper at the prisoner. "Look at the state of him, the filthy layabout! Look at his hair!"
He shot a nasty look sideways at Harry, whose untidy hair had always been a source of great annoyance to Uncle Vernon. Compared to the man on the television, however, whose gaunt face was surrounded by a matted, elbow-length tangle, Harry felt very well groomed indeed.
The reporter had reappeared.
"The Ministry of Agriculture and Fisheries will announce today --"
"Hang on!" barked Uncle Vernon, staring furiously at the reporter. "You didn't tell us where that maniac's escaped from! What use is that? Lunatic could be coming up the street right now!"
Aunt Petunia, who was bony and horse-faced, whipped around and peered intently out of the kitchen window. Harry knew Aunt Petunia would simply love to be the one to call the hotline number. She was the nosiest woman in the world and spent most of her life spying on the boring, law-abiding neighbors.
PIG LATIN VERSION !;
Arryhay entway ownday otay eakfastbray ethay extnay orningmay
otay indfay ethay eethray Ursleysday alreadyway ittingsay
aroundway ethay itchenkay abletay. Eythay ereway atchingway away
andbray-ewnay elevisiontay, away elcomeway- omehay-orfay- ethay
-ummersay esentpray orfay Udleyday, owhay adhay eenbay
omplainingcay oudlylay aboutway ethay onglay alkway etweenbay
ethay idgefray andway ethay elevisiontay inway ethay ivinglay
oomray. Udleyday adhay entspay ostmay ofway ethay ummersay inway
ethay itchenkay, ishay iggypay ittlelay eyesway ixedfay onway
ethay eenscray andway ishay ivefay inschay obblingway asway ehay
ateway ontinuallycay.
Arryhay atsay ownday etweenbay Udleyday andway Uncleway Ernonvay
, away argelay, eefybay anmay ithway eryvay ittlelay ecknay
andway away otlay ofway ustachemay. Arfay omfray ishingway
Arryhay away appyhay irthdaybay, onenay ofway ethay Ursleysday
ademay anyway ignsay atthay eythay adhay oticednay Arryhay
enterway ethay oomray, utbay Arryhay asway arfay ootay usedway
otay isthay otay arecay. Ehay elpedhay imselfhay otay away
iecepay ofway oasttay andway enthay ookedlay upway atway ethay
eporterray onway ethay elevisiontay, owhay asway alfwayhay
oughthray away eportray onway anway escapedway onvictcay:
"... Ethay ublicpay isway arnedway atthay Ackblay isway armedway
andway extremelyway angerousday. Away ecialspay otlinehay ashay
eenbay etsay upway, andway anyway ightingsay ofway Ackblay
ouldshay ebay eportedray immediatelyway."
"Onay eednay otay elltay usway e'shay onay oodgay," ortedsnay
Uncleway Ernonvay, aringstay overway ethay optay ofway ishay
ewspapernay atway ethay isonerpray. "Ooklay atway ethay atestay
ofway imhay, ethay ilthyfay ayaboutlay! Ooklay atway ishay
airhay!"
Ehay otshay away astynay ooklay idewayssay atway Arryhay,
osewhay untidyway airhay adhay alwaysway eenbay away ourcesay
ofway eatgray annoyanceway otay Uncleway Ernonvay. Omparedcay
otay ethay anmay onway ethay elevisiontay, oweverhay, osewhay
auntgay acefay asway urroundedsay ybay away attedmay, elbowway-
engthlay angletay, Arryhay eltfay eryvay ellway oomedgray
indeedway.
Ethay eporterray adhay eappearedray.
"Ethay Inistrymay ofway Agricultureway andway Isheriesfay illway
announceway odaytay --"
"Anghay onway!" arkedbay Uncleway Ernonvay, aringstay
uriouslyfay atway ethay eporterray. "Ouyay idn'tday elltay usway
erewhay atthay aniac'smay escapedway omfray! Atwhay useway
isway atthay? Unaticlay ouldcay ebay omingcay upway ethay
eetstray ightray ownay!"
Auntway Etuniapay, owhay asway onybay andway orsehay-acedfay,
ippedwhay aroundway andway eeredpay intentlyway outway ofway
ethay itchenkay indowway. Arryhay ewknay Auntway Etuniapay
ouldway implysay ovelay otay ebay ethay oneway otay allcay ethay
otlinehay umbernay. Eshay asway ethay osiestnay omanway inway
ethay orldway andway entspay ostmay ofway erhay ifelay yingspay
onway ethay oringbay, awlay-abidingway eighborsnay.


Ps. I have no recollction of whether I'm allowed to re-type the authors words but just keep in mind I'm only taking credit for the translation, not the full writing.
