Here's my suggestions for things to punch:
1. Meat on a hook (flies offscreen).
2. Solid Concrete Block (shatters into pieces).
3. Iron Girder (bends in the center from the punch).
4. Dumpster (on wheels so it rolls away).
The chris20855 voice acting company is open for business. PM me, and I'll be glad to help.
"Everybody has a plan until they get punched in the face." -Mike Tyson