...I guess I'll try... (Ravenclaw)
Funny one:
Sirius likes to play pranks when he's in a Muggle environment. He'll turn into a dog, watch the Muggles freak out and go get someone, then turn human just before they come back and just nod at them, like, 'Sup?' and watch how confused they get. James plays along sometimes, but not often, because the reactions to a random stag in a store tends to be more extreme than a dog.
Sad one (This is so weak...):
Every time Harry sees a wolf, he thinks of Lupin, about how he died just when he'd had Teddy. Every time he sees a deer or stag, he thinks of his parents and Snape, and their sacrifices. Everytime he sees a dog, Harry thinks of Sirius, and how he'd lost Sirius too soon. Every time he sees an owl, he thinks of Hedwig and wonders if he could have saved her. Every time he sees a house elf, he's reminded of Dobby, who lost his life because he'd saved Harry's... Even though Dobby had promised he wouldn't. Every time Harry walks into Hogwarts, he's reminded of all those who died to defend it... to defend him.
Favorite Character (I have so many... Guess I'll do Scorpius/Albus b/c I feel like it):
The reason Scorpius says he likes Rose is because he really likes Albus but won't admit it. Albus has liked Scorpius from the start but doesn't realize it (because, like his father, he is absolutely clueless). In their 5th year, Scorpius asks Rose to go with him to Hogsmeade. Albus is there being 'supportive' (read: Jealous as frick but he thinks he's hiding it really well). Rose just throws her arms up and goes, "No, Scorpius, I won't go with you, but my cousin will." and shoves them together. They're both extremely confused and embarrassed, but Rose kinda just tells them, "Go together. You'll have a good time." The boys protest but listen, and on the day of the trip, they come back to the castle, hand in hand. Rose (and the rest of the castle) just goes, "Finally."
