Make a deep slit along the back to ¨butterfly¨shrimps. Set aside.
Mix flour and salt in a bowl and whisk in the eggs, the beer and the melted butter. Let mixture rest, at room temperature, for 1 hour.
Before frying, open tails, pressing slightly, to resemble a butterfly.
Dip shrimp tails in the flour and beer mixture and fry them in hot oil for 3 to 4 minutes, or until golden on both sides. Fry shrimps in batches. Remove from the skillet and drain in paper towel.
Arrange on a serving dish and serve with Tartar Sauce.