How do you beat the dragon in LEGO Harry Potter Years 5-7 for the PSP? I've tried so many times, but I always end up dying! I can't find how to do it on any websites.
If the PSP version is similar to the other versions, you need to build a bull that contains a bell in order to scare the dragon and remove some of the flames. You can then walk by the flames, which triggers a cutscene, after which you are moved into the Lestrange vault.
If you watch from the 1:05 to the 2:20 mark of this YouTube walkthrough, you'll see how to accomplish it.