translating HTML encoding in filenames

I have big piles of files that we've downloaded in ages past (and not so past) whose names were HTML encoded, and I'd like to bulk convert them to readable text. I can, and have, used MacOS's Rename command and had it replace %20 with an space, then go back and replace %28 with (, etcetera, etcetera, etcetera...and I guess I could make an Automator script but those skills are almost nonexistent. So, does anyone know of an existing utility, terminal command, or Automator script that would accomplish this?