Morrigan's javelin

Morrigan's javelin is a ranged weapon exclusive to Deadman seasonals, requiring 78 Ranged to wield. It is part of Morrigan's equipment, a set of Ancient Warriors' Equipment, and is dropped by any NPC found in the wilderness as part of a global wilderness loot table, the chance being relative to the combat level of the NPC. It is unaffected by Ava's device's ammunation saving effect. Unlike other javelins, they cannot be used with a ballistae and are a standalone weapon.

Special attack
The Morrigan's javelin special attack, Phantom Strike, costs 50% of the wielder's special attack energy and has no effect against NPCs. Against players, the javelin will deal regular damage, but will also apply a damage over time effect to your opponent: every 3 game cycles, your opponent takes an additional 5HP of damage until the same damage dealt by the initial blow has been delivered.

Trivia

 * Ancient Warriors' equipment were originally added in a 2008, a year after the backup of Old School Runescape.
 * Morrigan's javelin, along with other Ancient Warriors' equipment was polled a possible drop from revenants, this poll failed.