They resemble fireflies or wasps, and mainly come out at night. They light up in the night air, making it easier to spot them from a distance. Wisps are found in Tephra Cave, on Bionis' Leg, outside Colony 6, and on the Fallen Arm.
The most powerful wisp is the Femuny Wisp, which is level 90, and resides in Tephra Cave. There are several species of Wisps.