Pour the beer into a large bowl. Sift the flour, salt, and paprika into the beer, whisking until the batter is light and frothy. (The batter may be used immediately or stored in the refrigerator for up to 1 week, but be sure to whisk it occasionally).
Remove the shells from the shrimp, leaving the tails intact. Wash and remove the black line running down the center if you wish (for aesthetic reasons only). Dry the shrimp and sprinkle with lemon juice, salt, pepper and a few drops of Worcestershire.
Heat at least 2 inches of oil in a frying kettle or electric fryer. Just before it reaches 375F, quickly dredge the shrimp with flour, shaking of excess then dip in the beer batter, coating well, and drop them into the hot fat (do this in 2 batches). When they are brown on one side - less than 1 minute - turn and brown them on the other side. Drain on paper towels. Serve hot with lemon wedges and watermelon pickles, if you wish.