Hellish Projectile (also known as Skull Missile) is a lethal Monster Skill and the signature move of Mephisto, the Act Boss of Act III in Diablo II.
Hellish Projectile looks like a white, blazing orb and is fired in a straight line. An 'incoming missile' sound can be heard as well.
Hellish Projectile can be very dangerous as it deals horrible damage, usually killing Hirelings and minions in a single hit. Players can expect to relinquish at least a third of their health. Mephisto only uses Skull Missile when at range, so closing in on him should remove the danger.
Damaging Skills
Fire — Fire Arrow • Fireball • Fire Bolt • Fire Hit • Firestorm • Fire Wall • Flame Circle • Hydra • Incineration Nova • Inferno • Meteor
Ice — Arctic Blast • Blizzard • Cold Touch • Fire Hit (Cold) • Freezing Charge • Glacial Spike • Hoarfrost
Poison — Poison Bolt • Poison Breath • Poison Cloud • Poison Spit • Poison Spray • Poison Sting • Poison Strike
Lightning — Lightning • Lightning Arrow • Lightning Globe • Red Lightning Hose • Shocking Hit • Spark Defense
Physical — Blow Dart • Charge • Corpse Cannon • Destructive Strike • Ground Tentacle • Leap • Leech-life Ball • Quill Dart • Slam
Magic — Bone Spirit • Hellish Projectile • Unholy Bolt
Non-damaging Skills
Indirect Attack — Blood Mana • Curses • Mana Rift • Minion Frenzy • Putrify • Spin Web • Stun
Spawning — Bone Prison • Festering Appendages • Lay Egg • Revive • Summon Minion
Self-effect — Bone Armor • Burrow • Fly • Frenzy • Heal • Teleport • Vile Effigy