Okay, a big black cluster of spots, of the nastiest type.
The ones that can spawn X-class solar flares.
(this one just barely got to "X")
From Space Weather:
Daily Sun: 11 Mar 11
Sunspot 1166 has a
"beta-gamma-delta" magnetic field
that harbors energy for X-class flares.
Here's Mudvayne's cover of King of Pain in a video dealing with another part of the energy spectrum: