Hunter's Grenade

Hunter's Grenade is a single-use skill. Unlike most other skills, the Hunter's Grenade deals no damage, nor does it affect the player. Instead, it only affects enemies with blueprints that you have not collected, turning the affected enemy into an elite version, dropping a Blueprint Extractor nearby, and disappearing. If a) all blueprints from the enemy type have already been acquired, b) the enemy is a boss, or c) no enemies are hit, the Hunter's Grenade will fail to apply its effects, allowing the player to pick it up for another throw.

Enemies struck by the Hunter's Grenade that have no Elite variant, such as flying enemies and immobile enemies, will instead be transformed into a standard Elite Zombie that still drops the desired blueprint when the extractor is used on them.

This item is unlocked from the Collector for 100 cells and, once unlocked, always appears in The Prisoners' Cells behind a gold door which can be unlocked for 7500 gold (or destroyed for a 30-kill curse).

Blueprint Extractor
The Blueprint Extractor is a skill produced when the Hunter's Grenade successfully activates which is only usable on the target elite enemy while its health is below 40%. Activating the skill within range of the enemy roots the player in place and channels a beam for 1.3 seconds, killing the enemy and forcing one of its blueprints to drop before disappearing. A message appears on-screen when the enemy drops below 40% health. Taking damage during the channel interrupts the process, so it is recommended to employ some means of gaining invincibility or preventing enemies from acting in order to ensure that the extraction process can be completed.

If the enemy is slain before the Blueprint Extractor can be used, the Extractor vanishes, the Hunter's Grenade is wasted, and the enemy drops no loot.