Millie Marotta is a popular illustrator known for her intricate and beautiful designs, often inspired by nature and wildlife. She is best recognized for her series of adult coloring books that blend artistic creation with mindfulness and relaxation. Her works feature detailed illustrations of animals, plants, and other natural elements, inviting colorists to add their personal touch to the art. Millie’s coloring books, such as "Animal Kingdom" and "Tropical World," have gained international popularity and have contributed to the adult coloring book phenomenon, helping users to unwind and express their creativity through her elaborate illustrations.