When Harry and the others went to Madame Malkin's to get their robes, they were amused to see a skinny blonde haired boy looking down his nose at them. As he left, Harry heard him mumble something about Weasleys having more children than they could afford. Harry couldn't pass up the opportunity, so he grabbed one of the spare wands and cast a small explosive hex, causing the kid to be splashed in mud all over his new robes. The blonde looked around indignantly, but Harry and the rest of the family were all immersed in picking out Harry and Ron's robes for the year. As soon as the twins saw Draco stalk off, they burst out laughing, clapping Harry on the back as he had gotten away with a perfect prank. Even Arthur had to smile, thinking of how he would love to humble arrogant Lucius Malfoy they same way that Harry had humbled his son.