In panel four, they are injecting the patient with “anti-dog-powers serum”, which prevents you from developing dog-themed superpowers after being bitten by a radioactive dog.

It clearly wasn’t a radioactive dog.

Rabies man

Rabies man

Does whatever

The rabies can

I didn’t get it until I read the transcript. I thought that the second panel was a jab with barbed wire (tetanus risk) and that the joke was basically “if your body is punctured, be sure to treat it by puncturing your body”.

I actually think I find that reading more fun than the intended one.