When the continents split eons ago, a population of Mokele-mbembe became isolated in what would become the Great Plains, adapting to the harsh environment by bonding with the emerging mesa formations. As the Thunderbird's power shaped the landscape, these creatures absorbed the earth's memories, becoming living repositories of the land's most ancient secrets, accessible only to those with the physical prowess to reach their remote domains.

The Mesa Mokele-mbembe possesses skin textured like weathered sandstone, capable of blending perfectly with the rock formations it inhabits and hardening to an impenetrable shield when threatened. Its long neck can extend from seemingly solid rock to observe intruders, while its massive legs can trigger localized tremors to test the resolve of those seeking its wisdom. Though primarily herbivorous, feeding on rare plants growing in hidden mesa crevices, it fiercely defends the sacred sites where the earth's most profound secrets are stored.

The Mesa Mokele-mbembe serves as the ultimate physical challenge for Earthbound Guardians, requiring them to overcome treacherous terrain and demonstrate their worthiness through feats of strength and endurance before revealing glimpses of the Thunderbird's earth-bound mysteries. Only those who prove their physical connection to the land can earn the creature's respect and access the primordial knowledge it protects.