I'm John
You mock someone by copying their voice and saying 'I'm John' like they're the dumbest person you've ever met.
He said, 'I'm John' in a fake voice, like he was the most annoying person on the planet.
She copied me and said, 'I'm John' like I was the dumbest person in the world.
He walked in and said, 'I'm John' like he was the most annoying person ever.