, take these, the deadliest of my minions. They shall aid you in your search."
A Hunter Killer
Hunter Killers are a special hydralisk strain. They are among the most elite and infamous of all zerg specialist strains.
Originally created and used exclusively by
Daggoth of the Tiamat Brood, Hunter Killers protected Sarah Kerrigan's chrysalis in orbit above Tarsonis.
Hunter Killers participated in the invasion of
Brontes IV, assaulting a hidden base held by the New Dresdin Outlaws.
Daggoth later sent a pair of Hunter Killers to escort Kerrigan when she infiltrated
Brood War, The dark archon Ulrezaj intended to use Hunter Killers in his attack on Shakuras. Using a technique to combine Dark Templar and zerg energy to create false, warped khaydarin crystals, he would control and summon hydralisks and zerglings from his base on Char and, using genetic stations on a space platform over Shakuras transform them into enhanced zerg with the false crystals. The technique rendered the Hunter Killers immune to the effects of the xel'naga temple.
The plot was foiled by heroes dispatched by
Zeratul's forces. 
Although Daggoth was a rival to Kerrigan during the conflict, Hunter Killers fell under her control on at least a few occasions. They were used to retake control of
hives under attack by renegade zerg and through a  psi emitter, Kerrigan gained control of a few on Braxis.
Four years later, Hunter Killers escorted Kerrigan during the
attack on the Moebius Foundation's main research campus on Tyrador VIII , and  the Terran Dominion invasion of Char.
Zagara can summon Hunter Killers in .
Heroes of the Storm
Hunter Killer decal
A Hunter Killer
decal is available in upon reaching level 22 with zerg. The decal is the outline of a hydralisk head. StarCraft II