When I asked what folks wanted to see here at SIB, some one mentioned they wanted to learn more about Terra-Man. I'm pretty sure they were kidding. But I don't care, you're getting a complete history any way. Why? Because I freakin' love Terra-Man, that's why. This, like most of the character profiles, is pretty long.

In a nutshell, he's a cowboy from outer space who rides a flying horse named Nova. That's right, he's a space cowboy; cue the Steve Miller.
Why is a space man dressed up like a cowboy and shooting lasers at Superman? Well, he wasn't always a space man. Tobias Manning started life as the son of an outlaw in the old west. His father's plan was for his boy to grow up just like him, becoming the greatest outlaw the west would ever see. During a heist the pair were pulling together, something bizarre happens. An alien who collects currencies from worlds the universe over shows up to steal their loot, accidentally killing Toby's father in the process. He's a thief, but not a killer, this alien, so he sets about making amends.

Toby grows up in outer space, and through bad comic science only ages twenty years while here on Earth one hundred have passed. He's been enhanced by the alien; given all manner of super advanced weaponry, and dubbed Terra-Man after his home planet. He's stronger, faster and can survive in the vacuum of space, he can teleport, change into smoke, and he's become a master thief, having learned all the alien's skills and secrets.
All of them:

That's a man who can hold a grudge, right there.
And that's how a hi-tech cowboy came to menace Superman on Earth. I don't care what any one says, that is a great origin. He'd fight Superman quite a few times in the next ten years being a fairly major foe of Superman's in the 70s and 80s.
The first time he came to Metropolis, Superman was in the throes of an illness that affects Kryptonians every 9 years on their birthday. Their encounter is pretty much 5 or 6 pages of Terra-Man smacking a sick Superman around with his hi-tech gear while Superman's powers act all screwy. Superman manages to keep his composure and win, but it's a tough fight. Terra-Man is especially cool over the course of this fight because for a very long time he doesn't say a word, he just stands there looking like Clint Eastwood knocking Supes around. Both his origin and this story appeared in Superman volume 1 # 249.

I'm not going to go over every single appearance of TM in detail, but I do want to pay special attention to his second appearance, Superman #250. Why? Because I had this comic when I was a kid and I must have read it a million times. Look at the cover. I
love that cover. When I was 8 years old you've no idea how much that emaciated old Superman creeped me out. I had this horrible image of Superman's skeletal hand clinging to that boot following that image and that made Terra-Man scary as hell to me.
The story begins with Terra-Man in prison, disgusted by the appalling conditions and primitive ways of 20th century Earth. He summons Nova, his flying horse, and escapes prison. He goes on a rampage drawing Superman out to capture him, and that's when Superman gets TM's brand. With the brand in place,
every time he uses one of his super-abilities, he ages. He can't be defeated by conventional weapons, so TM thought of something even Superman would have to contend with eventually- dying of old age.
Manning's having trouble of his own, though. The device that enables him to survive in a vacuum has been malfunctioning. The problem is the result of exposure to a man's experiments to make his own lungs impervious to smog. This fellow now exhales a gas that is causing Terra-Man's device to malfunction, and whenever the two are in close proximity to one another Terra-Man collapses, Terra-Man being defeated by the technology that helps commit his crimes. (If your curious, escaped the trap of the age inducing branding by stopping all of his bodily functions and the process reversed. I know that doesn't seem very exciting, but when I was 8 it blew my mind.)
Terra-Man's next few encounters with Superman had him robbing Superman of his ability to use his super-strength, tricking a cult into blowing up the moon and using the force from that explosion to destroy Superman (which is awesome Super-villainy), and forcing Superman into a duel for the life of his friends, which he didn't do very well at.

Terra-Man's biggest story was a three part tale in Action 468-470 where he manages to trick the world into believing he's killed Superman. He actually did something much more involved, tricking the man of steel into taking on a foe of his with technology and powers equal to his own.

Terra-Man shows up again to fight Superman, and on live television seemingly murders and buries him.
Days later, a hand claws its way from that grave, Terra-Man's hand. He's not killed Superman, he's stunned him and transformed him into an exact duplicate of himself. Why? Good question.
Remember when TM murdered the alien that raised him? Well, he had a brother, that alien, and he was out for revenge. Terra-Man got wind of this, so he thought he'd kill two birds with one stone. He makes Superman look like him, so the alien looking for revenge goes after Superman while TM lays low.
If Superman wins, the alien's in prison and TM can stop looking over his shoulder. If the alien wins, well, at least Superman's out of the way, right? This is actually a great example of a fun, action-filled 70s Superman story, and it even guest stars the Flash and Green Lantern.
These are the kind of Superman stories I grew up on.
He had a handful of other appearances before Crisis came. A team up with the Penguin against the World's Finest, a fight with Luthor, a story where he encounters the Terra-Man of another dimension who has magic based powers instead of tech based ones, and even a flashback tale that features a time traveling Superboy encountering the young Toby just before his fateful meeting with a space man.
His final appearance before the Superman universe redefining Crisis story is one of my favorites. Terra-Man shows up and points out that he's routed a giant projectile right towards Metropolis. Superman goes out into space to discover what it is while TM fights the Blue Devil on Earth. Superman realizes the projectile is moving much too fast to be a meteor. What is it? Awesome is what it is.

That's right, he's hijacked a space train and he's going to crack it open by smacking it right into the center of Superman's favorite city. That's a pretty great plan, I feel.
After the big reboot, Jerry Ordway came in and sucked all the fun out of him. There was a Terra-Man in this new continuity, but he wasn't a hi-tech cowboy. He was an environmental terrorist. He still had a slight cowboy theme to him, which consisted mostly of him saying "Pardner" and "Varmint" occasionally. He showed a up a couple of times fighting polluting businesses, eventually surrendering to Superman when one of his plans resulted in the death of a worker at the site of his attacks. This is what he looked like:

This version appeared in one last story a few years ago. Manchester Black, telepathic super-hero gone rogue, brainwashed and enhanced a small army of villains to go up against Superman. Dialog implies Manning had reformed and been released since his last appearance, but with Black's influence and new plant controlling powers he went after Superman one last time.
A new Terra-Man appeared in DC's weekly series Fifty-Two. He was sort of a cross between the two. He didn't really look like either, but he kinda acted like the old one. Kinda. He was only around for one issue. He robbed an airplane and seemed to have fun doing so. There was no environmental angle to him. Later in that issue, this happens:

A Captain Marvel villain rips him in half while the gore slaps Lois Lane in the face. Really, what the hell? Why was that necessary? "Hey, let's take a silly fun character created in a universe with worms who wear glasses and talking tigers in suits and have him mutilate a character who used to rob space trains! And then we can have his entrails land on Superman's girlfriend!"
Terra-Man made it out of the funnybooks a couple of times. In the too cool for words
Justice League cartoon, there was a two parter that featured the time-traveling villain Chronos. At one point, the League chases him to the old west where they team up with DC's classic western characters like Jonah Hex and El Diablo. Who do they team up against? An outlaw by the name of Tobias Manning who has stolen Chronos' time traveling device. He now had access to super-advanced weaponry and robotics which he used to take over a small town and run it as his own.

He's never called Terra-Man, as there's no reason for that name in this context, and his advanced tech come from the future instead of space, but it's him. Nova even makes an appearance at the end. It's a really fun episode, and I can't recommend the Justice League Unlimited series enough.
This version was awesome and if you're gonna modify Terra-Man's origin this is the way to go, I think. Dwayne McDuffie knows the score.
The
Legion of Super Heroes cartoon introduced a new version of Terra-Man in the semi-recent episode
Unnatural Alliances. This is probably going to seem way more complicated than it actually is, but here we go any way:
The Legion of Super Heroes is about a team of teenage super heroes that formed a thousand years in our future inspired by Superman. In the cartoon, a new character was introduced called Superman X. Superman X is a clone of Superman from even farther in the future who chases a villain from his apocalyptic time back to the Legion's time. Also from that future? A new version of Terra-Man.

No detailed origin is given for him. He's a self-repairing android; but still a cowboy, still flying around in space, still with blasting away with highly advanced weapons. He leads a pack of nameless other cowboy inspired robot thugs. He's pretty cool. His role in the story is pretty much that of a Terminator; sent back to the Legion's time to alter the future by eliminating some one instrumental to it.
So there we have it. He's a C-lister on his best day these days, but man, in the late 70s and early 80s, cowboys with lasers were something to be feared, pal.