Batman is known for, among other things, having a large array of bat-themed gadgets and vehicles that he uses in his never-ending war against crime. Every so often, some writer will attempt to explain where Batman’s stuff comes from.
One of those explanations was a guy named Harold.
Harold, last name eventually revealed to be “Allnut,” was born with kyphosis, a condition that leaves people with a severe curvature of the spine. In Harold’s case, that made him a hunchback. Combine that with the fact he was also a mute, and it turns out his family didn’t much care for him. He eventually ran away from home and had his first appearance during Denny O’Neil’s run on The Question. Harold is better known, if at all, as a Batman character, so he moved to Gotham City at one point where the Penguin realized that Harold was a mechanical genius. Sure, the guy couldn’t talk, but he could put things together in a brilliant manner and the Penguin was more than happy to put the guy to work.
Some time after that, Batman found Harold wandering around Gotham and took pity on the man, moving him into the Batcave to take care of Batman’s stuff and give the guy a place to live. This was during the run of writer Alan Grant, and Grant, among other things, seemed inclined to expand Batman’s supporting cast within the Cave as he also brought in a new Ace.
Harold’s role was basically to fix or build equipment for Batman. He was essentially a harmless, somewhat childlike, and likable enough guy who lived in the Batcave with the dog. In point of fact, Harold and Ace were the first to realize Jean-Paul Valley was off his rocket when he wore the Batsuit, prompting the two to hide deeper in the cave until Bruce Wayne came back.
Harold was last seen–for a while anyway–during No Man’s Land in a short story during which he emerged from the Cave, saw the entire city was, well, broken, and set off to start fixing it. The period after that story wasn’t really one that needed much of a guy like Harold, so he didn’t come back…for a while anyway.
Harold would return briefly in the Jeph Loeb/Jim Lee story Hush with his body fixed and able to talk. Apparently in exchange for being made “normal” by Hush, Harold needed to sneak into the Batcave and put a device of some kind on the Batcomputer. Harold did so, but was murdered shortly thereafter by the villains. Batman, seeing Harold just wanted to be normal, forgave the man and gave him a proper burial. His tombstone is where his last name was finally revealed.
So, you’d think that would be it, right? Harold is dead and…wait, DC did a big relaunch since then, two if you count Rebirth. Someone did manage to bring him back. And that would be writer Scott Snyder and artist John Romita Jr. Their Harold was once again a mute hunchback, but this one knew sign language and didn’t react like an easily scared child while he lived in the Batcave.
So, there you go. Batman gets his stuff from a guy named Harold. I rather prefer this story than, say, he gets his car from some random mechanic and his daughter.