In 2008, the World Wildlife Fund ran a campaign that used pixelation to represent the number of animals left for endangered species. One pixel represents an animal, so an image appears more pixelated when there are fewer animals left. Imgur user JJSmooth44 recently used more recent numbers to show the images for 22 species (sourced from the Animal Planet endangered species list).
The above is the image bengal tiger with 2,500 pixels. In contrast, the black rhino has 5,000 pixels:
Or, here’s the black footed ferret with 300: