They resemble rabbits due to convergent evolution
Viscacha or vizcacha (UK: /vɪˈskætʃə/, US: /vɪˈskɑːtʃə/) are rodents of two genera (Lagidium and Lagostomus) in the family Chinchillidae. They are native to South America and convergently resemble rabbits
"When I'm a small prey mammal and I've evolved to survive the barren rocky landscape by optimizing into a tan egg"
For posts about animals that loosely fit the description above. While the animal does not have to hit all the requirements, it should hit some of them:
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