grawl
Explanation
This comic is a Batman and Robin parody that plays with the comic book convention of representing swear words with random symbols (like #@$%!).
Robin rushes in to tell Batman that "The Joker kidnapped Commissioner Gordon!" Batman responds: "I swear, Robin..." but his actual swear word is replaced by the traditional comic-book grawlix symbols (#@$%!). Robin reassures him: "It's okay. This is comics. Swear words are replaced by punctuation marks."
Batman, intrigued, says "Huh. #@$%!" and Robin confirms: "Yeah, there's no way around it." But then the comic takes its twist -- the final panel shows Batman has figured out a loophole. He's written out actual mathematical or logical equations using the punctuation marks, essentially turning the censorship symbols into real notation. The symbols that were meant to hide profanity have been repurposed into their literal mathematical meanings.
The joke is a clever meta-commentary on the grawlix convention in comics. By taking the censorship symbols literally as mathematical operators and punctuation marks, Batman finds a way to "break" the system. It's a nerd-humor approach to a long-standing comic book trope, treating the visual censorship convention as a puzzle to be solved rather than just accepted. The comic's title "grawl" is itself a play on "grawlix," the actual term for the string of symbols used to represent profanity in comics.