Richard Maibaum, Johanna Harwood, and Berkely Mather
Given an infinite amount of time, a monkey at a typewriter would eventually write the complete works of a Shakespeare. Or a Simpsons episode. Or a Bond script.
And if he wrote a Bond script, he might make Dr. No a monkey…which is actually what he was in an early draft of the screenplay. (Source)
Surprisingly, this draft wasn't written by a monkey, but by a wolf—Wolf Mankiewicz (no relation to Joseph L. Mankiewicz, director of All About Eve.) Cubby Broccoli replaced Wolfie-boy with a new writer to monkey around with the script.
Entire Richard Maibaum, the man who would write thirteen lucky Bond scripts from Dr. No to License to Kill in 1989. With Harwood and Mather as script doctors, they brought the screenplay closer to Fleming's novel, with one exception—they took out the giant squid.
Bond doesn't like calamari, we guess. Or more like Bond couldn't afford it. In the climax of Fleming's novel, Bond is cornered by a giant squid in Dr. No's aquatic lair. But the budget wouldn't allow for any massive cephalopods, so Maibaum re-inked a climax, creating the one we see in the movie where Bond escapes from his cell's convenient air vent and saves the day. (Source)
Can you imagine if the squid had made the cut? Austin Powers would have had a field day with that one.