Aggro Icon

[Rhianu]

I like the idea that hostile enemies are easily distinguishable from non-hostile enemies, but I personally feel that this glaring Red Sun of Death™ icon is obnoxious and over the top.

Personally, I prefer the way WoW and Rift do it, which is by using color-coded names instead of an obnoxious marker.

Green name = friendly NPC who will not attack you
Yellow name = neutral NPC who will not attack you unless you attack it first
Red name = hostile NPC who will attack you if you get too close

Not only are the color-coded names less intrusive, they also create less clutter, and allow players to distinguish between THREE different types of NPCs instead of only two types.

Marking hostile NPCs was a good idea, but in this particular situation color-codes work better than icons.

An alternative method to do it could be to utilize a slow "pulsating" animation on the text outline, perhaps like this:

There are probably other ideas that could work too, such as a red glow around the text, or a red underline, or any number of things which are less intrusive than the Red Sun of Death™.