History:
The exact origin of the Eliminator is unclear. He was described as a robot (see comments), but given the magical nature of his creators, he would seem to be more magical in nature than mechanical. Eliminators are apparently a series of constructs used by the Witches of New Salem. According to the one the Fantastic Four encountered, an Eliminator had never previously failed in its mission.

(Fantastic Four I#184 (fb) - BTS) - After forcibly returning Agatha Harkness to New Salem, the Witches thought to erase all evidence of their existence from the outside world--this included the Fantastic Four, who were friends with Agatha; to this end--presumably under the direction of the malevolent Nicholas Scratch--they dispatched the Eliminator to Agatha's home on Whisper Hill (see comments) to slay them.

(Fantastic Four I#184 - BTS) - The Eliminator somehow traveled to New York City, where he picked off his first target--his tractor-beam pulled the Human Torch out of the sky (see comments), just as the Torch flew over the city. He then took his helpless captive back to Whisper Hill.

(Fantastic Four I#184) - Not realizing that the Torch had been attacked, but not wanting to wait for his return, the remaining three members of the FF headed off to Whisper Hill in the Fantasticar to track down Agatha, who had vanished with their son, Franklin. But as they approached, the Eliminator activated his tractor-beam, which tore their flying vehicle to pieces. The three plummeted to the the ground, but Sue cushioned their fall with an invisible force field.

   Reed, Sue, and Ben went inside Agatha's house and found the groggy Johnny hanging from a railing; but suddenly, the Eliminator burst through the wall and attacked them. Announcing his purpose, the Eliminator began his assault, and a struggle ensued for several minutes, until the Eliminator seemingly disintegrated Sue with his Omni-Beam. He then blasted Reed, seemingly killing him, then used his striking weapon to pummel Ben until his life-signs ceased; using his incendiary-jets, the Eliminator magnified the Torch's own flames, causing Johnny's powers to overload, and he vanished in a nova explosion.

   With his mission accomplished, the Eliminator proceeded to activate his own self-destruct device, which would destroy Whisper Hill as well. But as soon as he announced that the process was irreversible, the Fantastic Four reappeared, and Sue revealed that she had deduced that the easy way to destroy the Eliminator might be to let him destroy himself. She had used her powers to shield the group, and to cause them to vanish as they were seemingly destroyed. The FF then made tracks to safety, as the Eliminator--locked in place by his vacuum vents--exploded.

(Scarlet Witch IV#6 (fb) - BTS) - An Eliminator was sent to eradicate Wanda Maximoff.

(Scarlet Witch IV#6) - The Eliminator arrived in Lotkill through a portal and attacked the Scarlet Witch, his intended target. Scarlet Witch quickly opened a portal to the Chthonic Island to send the Eliminator and herself there so she could fight it far away from civilians. Scarlet Witch's new student Amaranth followed Scarlet Witch through the portal because she didn't want to be abandoned again. Eliminator resisted Scarlet Witch's spells, and after punching her, it used its Necrogaze, which nearly hit Amaranth. Scarlet Witch blocked the Necrogaze with a mystic shield and then attacked Eliminator with several hexes for having the audacity to try to hurt someone in her care. Amaranth accidentally distracted Scarlet Witch, who was grabbed by the Eliminator from behind. While the Glawackus oil on Eliminator's shell slowly removed Scarlet Witch's memory, Eliminator activated its self-destruct mechanism, but Amaranth touched Eliminator and caused a fatal error before Eliminator could eliminate Scarlet Witch. Amaranth then instinctively turned the Eliminator into an energy ball and absorbed the self-destruct spell.

When the FF landed by Agatha's home, the Thing discovered  what appeared to be a "metallic egg" -- presumably, this was how the Eliminator was transported to Whisper Hill.

The shape and border-coloring of the Eliminator's word-balloons suggest that he spoke with an unearthly timbre.

Although he was described as being a robot, the Eliminator seemed to express emotions (anger, contempt, surprise), so my guess is that he was actually a New Salem version of a cyborg (...and he kind of reminded me of the Terminator, who would first appear a decade later in the movies).--Ron Fredricks

New images by Ron Fredricks.