Don’t put anything important in this guy’s inventory if moving bases. Just... don’t. Make sure to check a list of what they’ll eat or by the time you’ve gotten two feet away from your old base there will be nothing left but regret.
Gachas are essentially living lootboxes and resource farms. They will eat anything (including stone, wood, or fiber) and turb it into crystals which can drop a variety of resources including black Pearl's, organic polymer, or obsidian, among other things. They also have a rare chance to drop higher-tier crystals which turn into upgraded armor and tools