That string of typographic symbols that substitute for swearing in cartoons? It’s called a grawlix.
The term is grawlix, and it looks to have been coined by Beetle Bailey cartoonist Mort Walker around 1964. Though it’s yet to gain admission to the Oxford English Dictionary, OED Editor-at-Large Jesse Sheidlower describes it as “undeniably useful, certainly a word, and one that I’d love to see used more.”
Well, @#$%&?!, that’s cool.