Cacography is deliberate comic misspelling, a type of humour similar to malapropism.
The term in the sense of "poor spelling, accentuation, and punctuation" is a semantic antonym to orthography, and in the sense of "poor handwriting" it is an etymological antonym to the word calligraphy: cacography is from Greek κακός (kakos "bad") and γραφή (graphe "writing").
A common usage of cacography is to caricature illiterate speakers.
References
Cacography Wikipedia(Text) CC BY-SA