The Sphinx of Galium is immediately recognizable for its large size and vividly colored wings. The forewings are generally brown or grey with darker striations and spots, while the hindwings display more vibrant colors, often with shades of pink or red. The moth has a wingspan ranging from 45 to 75 mm, making it one of the largest moths in Europe.

The life cycle of the Sphinx of Galium begins with the female laying eggs on specific plants, particularly on Galium species. After hatching, the larvae voraciously feed on the leaves of the host plants, growing rapidly and undergoing several molts before pupating. The pupa, developing in the soil or among dead leaves, is the stage for the final metamorphosis into an adult moth.

This species is widespread across Europe and parts of Asia. It prefers habitats such as meadows, woodland edges, and gardens where its larval host plants are found. The Sphinx of Galium is highly adaptable and can thrive in a wide range of environments, as long as there are suitable food sources and egg-laying sites.

The larvae of the Sphinx of Galium play a crucial role in the ecosystem, serving as a food source for various predators. The adults, with their intense flight and hummingbird-like hovering ability, are important pollinators for many species of wild and cultivated flowers.

Currently, the Sphinx of Galium is not considered an at-risk species. However, habitat loss and pesticide use pose threats to its survival. Conservation of natural areas and sustainable agricultural practices are essential to ensure the persistence of this species.