Who's This? You might know him as Max Mercury. He's on page 5 of Who's Who vol. XIX.
How you could have heard of him: In 1996's Flash #109, Mark Waid reintroduced Quicksilver as Max Mercury, avoiding the confusion with a now better-known Marvel character, and fleshed out his back story based on the few elements revealed in the original comics. Max became a principal player and mentor to both Wally and Bart (in Impulse) for the next 5 years.
Example story: National Comics #11 (1941) by Nick Cardy
I've seen very few Quicksilver stories, but those I have seen look like a lot of punching in this vein. As Max Mercury, he may be one of the most improved comics characters ever.
Who else? Let's stay in the Golden Age, to another published outside DC.