The 'Post This X' meme format is a modern evolution of the classic 'chain letter' trope, redesigned for the social media era. Usually featuring a low-quality or exceptionally cute image of a dog, cat, or obscure creature, the meme commands the viewer to share the image to achieve a positive outcome like 'instant happiness' or 'good luck.' It gained significant traction on platforms like Tumblr and Twitter during the mid-2010s, often used either genuinely to share wholesome content or ironically with bizarre, surreal imagery. The 'X' serves as a placeholder for any noun, making the template infinitely versatile for different internet subcultures seeking to spread a specific vibe or inside joke.