I made this icon to represent the Frost Wyrm projectile, it is meant for my Lich hero, he now has a new arrow ability called Glacial Breath where the Frost Armor ability would be (it was integrated into Dark Ritual, casting it buffs all nearby units with Frost Armor).
Glacial Breath: consumes 33 mana per attack to deal 25 bonus damage (+50% INT) on each attack, this damage splashes, applying frost.
PD: set under blizz.