Around 1990, my brother got a picture book out of the library. It was large (coffee table book sized, about a foot square) and probably relatively new. The contents were several dozen short fantasy stories, all by the same author and all illustrated in color. The lengths of the stories varied, from just one page to five or six. Many of them were quite interesting a creative, and I'd like to find the book again.
Here are a few of the stories that I recall:
A witch marries a king and turns a younger woman (either her step-daughter or her step-son's fiancee) into a sea serpent. The man who was going to marry the girl goes on a quest to find something that will cure the change, but he finds the serpent blocking his ship's return when he gets back. He manages to evade his transformed love and cure her; then, back at the king's court, he touches the witch with a fresh ash twig, which reveals her as a witch and turns her into a giant frog.
A boy needs to get three pieces of information, as well as three hairs from a man-eating giant. Fortunately, the giant's mother is nice and agrees to help the boy. She lets her ogre son fall asleep with his head in her lap, then pulls out a hair. When the giant wakes up, she asks him one of the questions the boy needed answered. Then the giant goes back to sleep, and she repeats the process twice more.
A boy out at night finds a little gnome creature with long blond hair and wrinkled skin (brown like a nut, I remember) trapped under a stone. The creatures thanks him for setting it free and offers to use its magic to help him, but tells the boy never to say thank-you. He asks it to cast a spell so that he does not need to do any work, but this causes his chores around the farm to be done by invisible ghosts. Everyone else on the farm is frightened, and they chase the boy off. He calls the gnome creature ("[Creature's name], come from the moors! I want ye!" was the formula), and tells it "I'll thank you to leave me alone." The creature sneers at the boy's foolishness and torments him for the rest of his life.