A Federation colony governed by Robert Wesley, threatened with destruction by a giant cloud creature in One of Our Planets Is Missing.
Mantilles is a Federation planet in One of Our Planets Is Missing, home to a large colony led by Governor Robert Wesley, a retired Starfleet officer. A vast cloud creature that consumes planets is approaching it.
Wesley has only enough ships to evacuate a tiny fraction of the population, a few of its children. Kirk takes the Enterprise inside the cloud, and Spock communicates with it through a mind meld, persuading it to spare Mantilles and leave Federation space.