Kerodon is an online textbook on categorical homotopy theory and related mathematics. It currently consists of a single chapter, but should grow (slowly) over time. It is modeled on the Stacks project, and is maintained by Jacob Lurie.
In the animal kingdom
According to Wikipedia:
The genus Kerodon contains two species of South American rock cavies related to capybaras and guinea pigs. They are found in semi-arid regions of Northeast Brazil known as the Caatinga. This area has a rocky terrain with large granite boulders that contain rifts and hollows where Kerodon primarily lives.