Create a vibrant and whimsical T-shirt design featuring a silhouette of a black panther under moonlight, incorporating a 3D vector art style. Blend in a cute and quirky essence with a bright, bold color palette against a black background. Employ a watercolor effect combined with digital painting techniques, adopting a low-poly approach for a modern touch. Use soft lighting to highlight the scene from a bird's-eye view, presented in an isometric style with a retro aesthetic. Focus intently on the panther character, capturing a photorealistic quality in 4K resolution, utilizing Cinema 4D for rendering. Present the image from a front-side perspective, adding subtle creative nuances to enhance the overall artistic expression.