At one point the characters go to get cake from a golden shower
"HAHAHA" laughed mystique "YOU WILL NEVER FUCKIN GET TE POWEERS."
In a stunning example of Mundane Utility, Harry and Shadow (the baby, not the hedgehog) ride Thestrals through a McDonald's drive-through in chapter 15. As the Dramatic Reading by LRM Reading points out, it becomes even funnier when one remembers that Thestrals can only be seen by those who have witnessed someone else dying, so unless that's the case for the McDonald's staff, they would only see Harry and Shadow apparently floating in midair next to the pickup window.
Just every insane metaphor, and simile they use. For example...
Ron slapped Hermione like a puppy when he pees on the floor.
"Dally is popping out babies like the west nile virus."
... Dumbledore and Mystique all tied up like hot pockets.