1. Ask him why he 'doesn't have such a cool scar?'
2. Laugh at him.
3. Wake him up by singing Beach Boys songs in his ear. 'Round, round, get around, I get around...'
4. Knit him things. Really hideous things.
5. Give him kangaroo-ears for a month.
6. Smile during Death-Eater meetings and say you taught him everything he knows.
7. Chew bubblegum all the time. Should he address you, your only response will be a series of huge bubbles in quick succession, the last of which will burst everywhere and make a mess.
8. Dance the Funky Chicken.
9. Ask him when was the last time he took a bath.