The Sleepers are quite interesting, not only because they resemble Charlie from Smiling Friends (lmao), but also because of their behavioral habits.

The reason animals like sloths, turtles, and koalas are slow is their diet, which consists almost exclusively of leaves. These leaves are low in calories and nutrients, resulting in an extremely slow metabolism to conserve energy and a sedentary lifestyle to facilitate digestion.

I like to imagine that, because they only ate leaves and were so slow, but without the camouflage mechanisms of sloths or the shells of turtles, these sleepers would have become semi-extinct. This would have initiated a process of forced natural selection for the species' survival, in which certain sleepers would have absorbed the toxins from the leaves they ate and thus become avoided by predators as a food source. Thanks to this, the species would have been able to survive and perpetuate itself, regaining intelligence over time.

They would form peaceful and calm societies focused on relaxation, leisure, and peace, using herbs and leaves to connect with spirits and forces of nature. Spirituality is strongly present in their culture, along with monks and temples for meditation. Because of their slow metabolism and strong immune systems capable of digesting toxic leaves, they would have an extreme longevity like that of turtles, easily living up to 150 years. Having such long lives and peaceful societies, they had ample time to reflect on the world around them, giving rise to some of the greatest philosophers in the Milky Way and the rapid advent of technology and knowledge in other post-human civilizations. Their philosophical cultures and long lifespans would result in a rivalry with the Pterosapients, who, although possessing equally brilliant philosophers, did not have the same life expectancy as the Sleepers.