Warning: Video contains coarse language
Here's a look at the dust-up:
The fan reportedly started it, according to Madeline Kenney of the Chicago Sun-Times, and Chicago police confirmed they were notified of a disturbance at the arena after the man allegedly began punching the mascot and put him in a headlock.
But Tommy Hawk is clearly no pushover, responding with some blows of his own that have since made their rounds on social media.
A Blackhawks spokesperson said the team is aware of the incident and will look into it.
"We are gathering the facts and will have no further comment at this time, pending our investigation," the representative said.