What is in this image? Describe it as if you were explaining it to someone from the 15th century.

This image contains a fantastical scene with two mythical creatures drawn in black outlines against a blank background. The primary creature resembles a large, docile beast, laying on the ground with an expressive face that suggests gentleness. This large creature has features somewhat like those of a lizard, with a streamlined body adorned with patterns of circles, a long tail, and a row of small, sharp peaks running down its head and back, evoking the spines of a dragon. It has limbs with rounded ends, indicating feet.Mounted on this large creature is a smaller, similarly mythical creature designed to mimic the structure of a horse, but with exaggerated features such as a broad smile, large circular eyes, and spiny embellishments running along its neck, head, and back, parallel to the larger beast. This small figure seems to be in motion, possibly depicting a jovial moment as if it is riding the larger creature.Both creatures are composed of simple lines and shapes, making them look whimsical and friendly, and they are set in an open space indicated by a few simple clouds floating in the sky above them. The overall scene suggests a play or a story from a children''s fable, inviting the viewer to imagine a world where such benign, mythical beasts roam freely and interact joyously.