If you look closely, you can see that Homer's little squiggle of hair and right ear resemble an 'M' and a 'G.' Those letters stand for the name of his creator, Matt Groening! Groening originally designed the features to resemble the letters much more closely, but he thought the ear was too distracting. He still draws the ear as a 'G' when he draws pictures of Homer for fans though!
(Sources: 1, 2)