It is interesting to note that the Medusans are one of, if not the only, noncorporeal beings that are active members of the Federation. Because of their different structure and correspondingly different sensory systems they are much better suited for space travel then most members of the Federation. However, it is very difficult for the Medusans to interact in a meaningful way with the mostly humanoid Federation. This is due to the fact that the Medusans have not completely shed their physical form and must always have it with them. This physical form is said to be so hideous that a humanoid viewing it without protection will be driven insane. An interesting side note is that while the Medusans body is grotesque in the extreme, their advanced mind - when viewed by those with telepathic abilities (i.e., Betazoids) - appears to be quite beautiful.
Medusans are a benevolent noncorporeal life form, but they normally prove lethal to any humanoids who see them.
Medusans can find their way across space time even from outside the boundaries of charted space to arrive precisely at their desired location.
Safety measures, such as clearing personnel form any corridors the Medusan is to pass through, are designed to minimize crew contact with the hazardous guest Teleportation leaves Medusans unsettled, despite their protective containers.