Publishers Bloomsbury have re-designed the old adult covers to make the early books look like the recent hardback version of Order of the Phoenix.

So far around 10% of the millions of hardback OOTPs sold have the mysterious looking adult sleeves.

They've also designed a special school satchel-style bag to put the two Comic Relief books into.

Those books - Fantastic Beasts and Where to Find Them and Quidditch Through the Ages - have raised £15.7m for Comic Relief so far.