Spawns in between a large rock and a small rock just west of the guard tower on the hill outside of Aegirhamn, near a group of Myggas. Looks like a small, glowing purple orb.
I got too close, and received the message:
"A strange globe of light seems to have latched onto you. You immediately feel as though the life is being sapped from you!"
I turned to sprint, got about 2 steps, and it nuked me for 125.