An apparent glitch in Lego Harry Potter: Years 1-4 (at least, it's in the old Wii version) allows Crookshanks to nudge dementors off ledges, from which they are unable to return -- discovered in a pinch when Harry got stuck halfway through a level and the dementors had to be dealt with in order to continue the level, something that seemed impossible without the Patronus charm (but wasn't). This method is a lot slower, but if you want to try it just for fun, or you're in a likewise pinch, here's how to do it.
1. Put Hermione in Crookshanks mode.
2. Make sure she's giving Crookshanks lots of space to work in, then release Crookshanks.
3. Move Crookshanks to the nearest dementor (notice that Crookshanks doesn't lose hearts when close to it the way other characters do).
4. Run up against the dementor and towards the nearest ledge.
5. If you keep pushing, the dementor should slide over the edge and not come back.
6. Repeat with other dementors (if necessary).
7. Proceed through the level with pride in your success.
If this didn't work, it's possible it's only operable in the level I tried it in (The Dark Tower, I think), or maybe it only worked in the old version (and not the remastered one). Also, it takes some practice; sometimes, Hermione gets in the way, or the dementors are hard to push. But it IS a helpful little glitch (and quite entertaining, might I add).
1. Put Hermione in Crookshanks mode.
2. Make sure she's giving Crookshanks lots of space to work in, then release Crookshanks.
3. Move Crookshanks to the nearest dementor (notice that Crookshanks doesn't lose hearts when close to it the way other characters do).
4. Run up against the dementor and towards the nearest ledge.
5. If you keep pushing, the dementor should slide over the edge and not come back.
6. Repeat with other dementors (if necessary).
7. Proceed through the level with pride in your success.
If this didn't work, it's possible it's only operable in the level I tried it in (The Dark Tower, I think), or maybe it only worked in the old version (and not the remastered one). Also, it takes some practice; sometimes, Hermione gets in the way, or the dementors are hard to push. But it IS a helpful little glitch (and quite entertaining, might I add).
