Splash from Captain America Annual #3 (1976), script and pencils by Jack Kirby, inks by Frank Giacoia and John Verpoorten, colors by Janice Cohen, letters by Gaspar Saladino
Nor is this guy the Thing from the Black Hole Star. He's the Combatron, who is a victim of his predictive naming. No one ever calls a hideous monster from a distant galaxy the "Poetron" or the "Kissytron," and I think that's a pity for all of us sensitive comics readers.
Here's the Hunters of the Captive, the guys who are chasing The Thing from the Black Hole Star™, and they have some pretty impressive KirbyTech all around them, don't they? Not to mention the most stylish and with-it headgear, surely purchased direct mail-order from The 5000 Hats of Jack Kirby.
So they send these guys to hunt down the T.F.T.B.H.S., and pity the poor Captain America who gets in their way. Behold...the Magnoids!
The Magnoids are of "inorganic origin" (thus qualifying them as proper KirbyTech), created from "magnesium imitating flesh and blood." That word "magnesium" made my little fuzzy ears pop up. As pretty much every first year chemistry student (or avid watcher of MythBusters) would know, magnesium is, despite its presence in the human body, highly volatile.
In other words, magnesium explodes and burns upon contact with water. (So please: do not put magnesium ice cubes in your drinks.) Which makes it an odd choice to build killer robots out of, don't you think? About as likely as those aliens in M. Night Shyamalan's Signs whose Kryptonite is ordinary tap water. Kinda picked the wrong planet to land on, then, as Prince Namor the Sub-Mariner might tell you.
On the other hand, as that Wikipedia entry on magnesium taught me, "the relative abundance of magnesium is related to the fact that it easily builds up in supernova stars". Which makes it an altogether-not-impossible choice for your Magnoid-construction-metal of choice, especially considering the Hunters of the Captive's origin and that that they're pursuing
Cap, master of strategy, instantly intuits that these are heartless machine killers. Therefore, the gloves are off! He can destroy them with impunity, and with his shield...they're just robots! (Or so he'll report later before the Supreme Court case of Rogers v. Magnoids.)
Metallic, inorganic, and robotic the Magnoids may be, but Captain America is wrong: they do have an inkling of human emotion, as can be seen in these two panels: they are curious and they're not impressed. Also: they are very good at making Cap go "Ugh!! Ugh!!" and "Hey!--Oww!"
Powerful they may be; extra-terrestial they are of origin, but they're no match for the strength and will of America's Super-Soldier, who handily beats them at arm-wrestling, immediately inspiring the Sylvester Stallone motion picture Over the Top.
Oh, by the way, I know you haven't gotten the question posed waaaaay up there at the top of the post. The Thing from the Black Hole Star, and the villainous killer alien the Magnoids have been sent to apprehend, is this guy: Threkker the Captive! He's got a big ego, a big jaw, and a big hate-on for the rest of the universe. You can tell he's evil because he's got those patented Kirby bushy-pointed Eyebrows of Doom. Still, despite his evil origin and his dire destructive nature...he nevertheless has pretty good dental hygiene, huh? And I can't imagine that it's easy to floss those things, either.
Luckily Cap doesn't have to wait for Thor and Iron Man and the Wasp to arrive to save his all-American bacon...it is the Captain America Annual, after all...the Magnoids arrive en masse to take Threkker captive. Go Magnoids go! They turn out to be on Cap's side! How does this make you think about Magnoids now, folks?
The Magnoid subdue Threkker the Captive through their powerful future technology and advanced galactic tactics! That is...they all dogpile on him.
Naturally, upon his capture Threkker refuses the right to remain silent. Oh boy does he refuse to remain silent.
Judge, jury, and robot-cutioners, the Magnoids shoot Threkker into a star going nova. To be fair, Threkker appears to be enjoying it, laughing all the way. Well, he's certainly a good loser. Also: now inside the supernova, he can mine plenty of magnesium! See: comics books are your best educational value!
Naturally, after dying in an exploding star, nobody ever saw Threkker the Captive, ever again.
Until Quasar #16.
Panel from Quasar #16 (November 1990), script by Mark Gruenwald, pencils by Mike Manley, inks by Dan Panosian and Keith Williams, colors by Paul Becton and Joe Rosas, letters by Janice Chiang
And Starblast #1.
Panel from Starblast #1 (January 1994), script by Mark Gruenwald, pencils by Herb Trimpe, inks by Ralph Cabrera, colors by Mike Higgins, letters by Paul Becton
So, except for Threkker's inconvenient return from being shot into an otherwise inescapable exploding supernova, the Magnoids are pretty capable. What do you have to say to that, Captain America?
'Nuff said, Cap!