Sandro has a red coat and darker red mane, as well as dark blue markings on his body and muzzle resembling a zebra's.
There are conflicting accounts of Sandro's behavior and personality. He has been described as both timid or a boisterous partygoer.
Sandro was created in the future by a scientist as a cyborg. Considered imperfect, the scientist scrapped Sandro and sent him to the present age.
Assuming he had amnesia, he wandered about for awhile, trying to find out who he was; eventually, he unwittingly met another cyborg of the mad scientist's design, but, after questing for their identities together, the other glitched and tried to murder Blitz. Barely overcoming his surprise assailant, he discovered the robotic nature of his former ally, and realized it was highly probable he was robotic, too. However, wounded, he was later assailed and slain by some bandits.
It was not, of course, the end of his adventure. Some good scientist ponies came from the future after learning of the jettisoned robots, both to escape the growing power the mad scientist had attained and for hope finding the robots could gain them salvation. They found Blitz, and, bringing him to a makeshift lab, found his memory chip was mostly damaged. They copied what they could from it, but could only give incomplete details to him. Realizing he could not help them in such a condition, they decided to let him live a normal life, and, after generating an imagined childhood in his mind, sent him on his merry way.
Still, however, they needed to prepare for the day the mad scientist would, too, go back in time to take over Equestria from the past, and created several clones of Blitz- with these, they would be ready.
Bored scientists, however, make for bad or silly decisions, and they decided to sometimes send out and recall the clones, who, too, were led to believe they were normal ponies. Some were tweaked in personality; some were made shy, some loud, and even some more... different.