Will-o'-Wisp (Dungeons & Dragons)

In the Dungeons & Dragons fantasy role-playing game the will-o'-wisp is a malevolent entity which makes its home in swamps and bogs. This aberration consists of a bizarre, spongy substance which hovers telepathically in the air, enveloped in a mysterious glow of yellow, white, green or blue.

Characteristics and habits
When encountered in its swampy homes, the will-o'-wisp typically takes the form of a faintly glowing lantern hovering in the air. In order to sustain itself, it must feed off upon the electricity generated by the brains of people who realize they are about to die. It lures those who wander into its midst by taking the form of a guiding light (the creatures can alter their forms, size and color to a small extent), and then have them wander into deep pools where they get sucked down and drown. The wisp then feeds on the energy generated. If the creature cannot lure victims into a trap, it is also capable of generating electricity on its surface to act as a touch attack. If the creature does not wish to be seen, it is capable of extinguishing its glow.

The will-o'-wisp cannot speak, but it is capable of vibrating to make a ghostly, shallow sound which sounds like strange forms of Common and Auran. When communicating with other will-o'-wisp, it does not make these sounds, but instead communicates with complex changes of its light and size.

The will-o'-wisp is regarded as chaotic evil in alignment.