Absolutely! The Fair Use doctrine also covers things like review, commentary, and critical analysis. Though making a character out of the last ones could be challenging.
(Not a lawyer, but I used to have to keep up with copyright stuff for work.)
Unfortunately, most famous comics characters are also trademarked. Trademarks are a whole separate kettle of fish, and, unlike copyright, must be defended or you can lose them (c.f. Kleenex, Aspirin, Heroin). This I am no expert on, but one of the biggies is "Could a (really stupid) consumer confuse your product with mine?"
Awwww!
I still think that revelation was a turning point, but I guess we'll never know for certain.
I hate that settlements usually stipulate secrecy.
There are some nifty card tricks you can do with the blank one. And, yes, the ad one is good to practice throwing!