This is a vintage-style illustration of a wallaby, a small marsupial native to Australia. The wallaby is depicted in profile, standing on a rocky outcrop. It has a sleek, dark brown coat on its upper body, transitioning to a lighter reddish-brown on its lower body and legs. Its long, curved tail is a deep black. The wallaby is looking towards the left of the frame. The background features a rugged landscape with a waterfall cascading down a rocky cliff. Sparse vegetation, including shrubs and grasses, dots the terrain. A distant hill or mountain range is visible in the background, adding depth to the scene. The overall style of the illustration is reminiscent of 19th-century natural history illustrations, with a focus on accurate depiction and detailed rendering. The color palette is muted and earthy, with shades of brown, gray, and green dominating the composition. The illustration is signed at the bottom with the name of the animal: 'Petrogale Penicillata'.