Create a series of black and white illustrations for a toddler's coloring book in a cartoon style. The theme is 'Dragons and Mythical Beasts'. Each page should feature different friendly and cute mythical creatures like dragons, unicorns, griffins, and phoenixes. Ensure the characters have large, expressive eyes and smiling faces. Include simple backgrounds such as castles, enchanted forests, and magical mountains, but keep the details minimal and outlines clear and bold for easy coloring. The overall tone should be whimsical and gentle, with characters depicted in playful and endearing poses, suitable for very young children.