What does the exclamation icon mean in the lower left toolbar?

[mmille14]

It looks like this ((!))

[Kopejka]

its a skill that you learn
Basically you whistle to attract 1 enemy to come to you

[Milchschnitte]

It's the skill "lure" you bought.

[kahuff345]

Hi,
You can attract enemies with it, works better than rocks on lower difficulty settings

[joxertm22]

It works on any diff, just press F while hiding in grass near trashmobs to whistle, when they approach, instakill.

[mmille14]

Oh, that's Lure, doah!