The King Swallowtail's scientific name is Papilio Thoas. Sometimes it is called Thoas Swallowtail. You can see them flying year-round in the southernly states of the U.S and in Mexico, Central America and also in South America as far down as Argentina.
King Swallowtails look like Giant Swallowtails. The King Swallowtail has four tiny spots on the trailing edge of the forewing, whereas the Giant Swallowtail has three spots