From the Super Mario Wiki, the Mario encyclopedia
Moe-Eye Habitat is a location in the Sand Kingdom in Super Mario Odyssey. It is a poison oasis where the vast majority of Moe-Eyes are found. The location is mandatory to visit in order to collect the Moon Shards in the Sand Power Moon, as most of the mission's Moon Shards are found there. To find the Moon Shards, Mario must capture the Moe-Eyes and use them to find invisible platforms found throughout the poison oasis.