"Hiii..."
"I'm, I'm, I'm like a dog chasing cars. I, I wouldn't know what to do with it if I caught it!"
The iconic "Let's put a smile on that face!" and "Why so serious?" lines are pretty standard Joker fare too, just with a slightly darker spin this time around.
Someone mentioned on another board that it would've been hilarious if the copycat turned out to be Keaton. I agree.