Chrono Cross also has summons; there are 12 total (two for each color element). They are:

Unicorn (White)
Saints (White)

MotherShip (Black)
GrimReaper (Black)

Sonja (Green)
Genie (Green)

Golem (Yellow)
ThundaSnake (Yellow)

RedWolf (Red)
Salamander (Red)

FrogPrince (Blue)
BlueWhale (Blue)

Also, I'm not sure you can call Elidibs' 'Midgar Swarm' from FFT a summon, since it can damage him as well. In FFT, all summons damage only enemies or heal only allies. This is supported by the fact that summoners can learn the hidden summon Zodiac from him, but not Midgar Swarm.