In a large bowl, whisk together the cornmeal, flour, sugar, baking powder and salt. Add the creamed corn, milk, egg and onion; stir until just combined.
Fill a large pot with enough oil to reach a depth of 2 inches and heat over medium-high heat until it registers 350 degrees on a deep-fat thermometer. Working in 3 batches, and using a soup spoon, drop heaping spoonfuls of batter into the oil. Fry, turning occasionally after the hush puppies rise to the top, until browned, about 5 minutes. Using a slotted spoon, transfer to paper towels to drain. Serve warm.