Art from "Comic Features" issue #33 features cartoons that Marvel Productions pitched, but never got produced.
Mark Evanier on the Daredevil series:
I wrote the bible and pilot and pilot for that Daredevil cartoon series…or rather, I should say I wrote a bible and pilot for it. Others had done several of each and ABC wasn’t happy with any of the approaches. I was hired to take over and much of what I did involved throwing out concepts and alterations that others (including Stan Lee) had done to the basic premise. By that point, there were a lot of characters and gimmicks a lot less faithful to the premise than any superdog. I basically turned it back into the version of Daredevil drawn by Wally Wood. Matt Murdock did have the seeing-eye dog, which was not an illogical thing for a blind guy to have, and the dog sometimes aided him a la Lassie but wasn’t any sort of superdog.
ABC agreed to buy the series and it was even announced in the Hollywood trade papers…but then a gent who worked for Marvel said the wrong thing to a top exec at ABC who, I suspect, was looking for an excuse to not buy the show and to give the time slot to another project that he preferred. Whatever the reason, we woke up one morning to find that Daredevil was off the schedule, never to return. My agent and I had a brief argument with Marvel over a bonus I was to receive if the series was picked up…and they finally paid it to me because they had to admit the series was picked up. It was just dropped again.
I think NBC later considered the show but networks generally don’t like picking up things that their competitors have passed on.