The animal that can sleep for up to 3 years is the snail. Snails exhibit an extraordinary survival mechanism by entering periods of dormancy such as hibernation during cold conditions or estivation during hot and arid conditions. During these times, they burrow deep inside their shells and seal the opening with a layer of mucus to conserve moisture and energy, allowing them to survive long periods without food or water, sometimes up to three years, although this is quite unusual and depends on species and environment.
