Fourth most iconic Final Fantasy summon?

Bahamut, Ifrit, and Shiva are the mainstays, but who comes after them? At one point, I'd have said Ramuh, but he gets left out of a lot of modern FF games, so I'm not sure it's him anymore.

(Also we aren't including summons that are derived from common Final Fantasy beasts, like chocobos, moogles, tonberries, or cactuars or important characters like Gilgamesh)