J3-Golem

J3-Golem is the final boss of the planet Jupiter. He can be found on the mission Themisto. He has a possibility of dropping one of the following on death: Volt Helmet, Volt Chassis and Volt Systems blueprints and Neural Sensors.

Appearance and Abilities
The J3-Golem uses Ancient Disruptor's Pre-Update 9 model, which resembles a deformed corpus crewman with multiple tumors around its body. However its behavior differs completely from other Infested.

Instead of a charge attack like other Ancients, the Golem instead uses a pull attack similar to the Pull ability of Mag when a player gets in range. This will pull the player right to him and allow him to either melee with claws or release a cloud of poison around him, close to impossible to avoid. As for ranged attacks, the Golem can also toss projectiles that explode into toxic fumes, dealing poison damage on hit or if the player walks into the fumes.

While the Golem has no shields, he makes up for this by having a decently large amount of health. All poison damage inflicted by him ignores shields and damages health directly, just like Toxic Ancients and Noxious Crawlers.

The J3-Golem, like many bosses, has unique taunts. Here is a list of them:
 * "Unburden yourself from this mortal coil, . Join Us."
 * "Why do you destroy us? We are your flesh."
 * "We are countless. Consume us. Be reborn."
 * "We embrace you. Why do you defile us?"

The current J3-Golem is a placeholder and will hold a new appearance alongside new abilities and fighting style in a later update. Future appearance has been hinted at as being eight stories tall, the largest enemy in the game by far.

Strategy
Due to the Golem's poison-based attacks, extra caution is required to avoid having your health drained rapidly. While his grenade spam is already dangerous on its own, the most annoying and threatening of his abilities is Pull, which can yank you out of cover into the open and also put you in range of his poison cloud attack. As such, using long-range-high-damage weapons such as the Snipetron or the Lex are advised, so you can shoot him while staying out of his Pull's activation range. Staying far away from him (40 meters or more, the grenade reaches 30 meters on flat ground) will also make his grenades miss all the time, making other infested the only worry through the fight.

The Golem is best fought while standing behind short obstacles approximately up to your waist. As the Golem aims its grenades directly at your feet, they will impact the obstacle and leave you unharmed, while you can freely shoot at him. Even if he walks close enough, the obstacle will also prevent you from being pulled out.

When playing this map solo, an effective method is to kite the Golem to one end of the top walkway, then run to the opposite end and climb onto the orange crates. He moves so slowly that you can take your time shooting his legs. Once he gets to roughly 30m away, jump down to the ground floor and run over to the other end of the top walkway then climb onto the orange crates again. He will regenerate a bit of his health when you do this, but it is fairly negligible.

Another solo strategy, is a close-kite method by keeping at least a 1 meter distance and at most a 2 meter distance from Golem. If the player is within a 1 meter range of Golem it will attempt to use its claws to strike the player. If the player is further than 2 meters from Golem it will use the ability to pull the player within melee range. By standing in  this virtual blind spot, Golem is unable to attempt any other attack besides Miasma. Casting Miasma forces Golem to stand in place for a split second. In order to maintain this distance between the player and golem, the player respectively walks and stops whenever Golem does.

Excalibur's Slash Dash ability is excellent for making a quick escape after being pulled.

With Mag, using her Crush ability will disable J3-Golem, breaking his legs and disabling his movement almost completely. He then can only use his Poisonous Gas and Pull abilities.

Trivia

 * J3-Golem is the first Infested boss, and was the only Infested boss before Update 6, which added Phorid.
 * J3-Golem is supposedly centuries old, which would probably make him the oldest boss in the game lore-wise.
 * It is said that J3-Golem was first created by the Orokin themselves as a weapon in an ancient war against "The Sentients" (the name sentients leads us to believe that they were some type of machine), it is possible that J3-Golem was created by the Orokin and then infected by the Technocyte Plague as we know (as of Dark Sector lore) the origins of the plague to be cold war Russia.
 * J3-Golem is renamed as Ancient Infestoid if encountered in an Alert mission.
 * After Update 7 this boss can drop not one, but two packs of resources (with a chance about 15-25%). One of them contains Jupiter resources (circuits, neural sensors or salvage) and the other contains an Orokin Cell.
 * The J3-Golem might be partially made from consumed Tenno, hinted at by asking the Tenno, "Why do you destroy us, we are your flesh" (or that the Tenno are also infected with the Technocyte virus just like Hayden Tenno in Dark Sector (confimed by the devs to be the first tenno in live stream 10).
 * As of Update 9, J3-Golem can be found in the Grineer Asteroid Base.