Some of the Time Lord Fairy Tales take a old story and do something different with it. Some don't, and all they really do is change the names and substitute a Doctor Who monster for the original. This is one of those.

Jack becomes Jak, the beanstalk is now a wormhole, and the Giant is replaced by Nimon. One major difference is that Jak gets to keep the cow! Rather than selling it for some magic beans, he stops on his way to market to help a dying man and gets money in exchange for the promise to destroy some unknown device. He can't figure out how to destroy it, so the wormhole does indeed open, but the story pretty much plays out the same otherwise.

Could be a fine bedtime story for a tot, I suppose.

Another just fun story, it feels less like a fairy tale more like a story that a parent would make up at bedtime for a child to fall asleep to, but it captures that essence perfectly.

It does strike me as odd as to how none of these fairy tales seem to be about gallifeyans, given that's where they're meant to have been told, but eh, they're still fun!