A Wisp of Pale Sheen
The Dead Marshes#108 (x3/x1)

When Revealed: Place 2 resource tokens on Gollum. Any player may exhaust a hero to reduce this effect to 1 resource token.

Escape: 4

Presently it grew altogether dark; the air itself seemed black and heavy to breathe. When lights appeared Sam rubbed his eyes: he thought his head was going queer. He first saw one with the corner of his left eye, a wisp of pale sheen that faded away...
–The Two Towers