Black-and-white Line Drawing Illustration

Create a black-and-white line drawing illustration for coloring, formatted to fit standard 8.5x11 inch paper without any border around the edges. The design should be clean and straightforward, using smooth and defined black outlines without any shading, grayscale, or colored areas, on a completely white background to make coloring easy. The scene should feature a playful otter swimming in a river surrounded by tall, leafy reeds. Small fish should dart through the water, while a dragonfly hovers above. The riverbank should include scattered rocks and a few wildflowers, beneath an open sky with soft sunlight filtering through. Include, in the lower right corner, a small fully colored version of the illustration as a reference, showcasing bright colors and a cheerful appearance. Intended for children aged 6 to 9 years old.