There is a pokemon found on trails crisscrossing deserts, a pokemon that might at a distance be mistaken for scrap metal, which is also the substance on which, when in cities, it primarily feeds. Orthworm, although obligate metallivores, are not in truth picky eaters; meteoric iron, abandoned mines, battlefields after battles, and even smaller steel pokemon are often prey for these beasts, who feast as if struck with insatiable hunger.
It is possible to ride an Orthworm the length of the Great Paldean Desert, or even the Sahara, for these strong and surprisingly wide pokemon are more than capable of carrying loads of trade goods. However, even tame Orthworm refuse to forage or hunger while transporting others, and demand to be fed by trainers. Orthworm's immense appetites make it difficult to run such caravans at a profit, and traders who tried to cheap out on their food often found themselves eaten by these hungry pokemon. The feral Orthworm then diverted their paths from well-worn trails to whatever spot of arid, empty desert they imagined to be the most promising source of ancient metal deposits.
The coming of the Orthworm was long viewed by merchants as a sign of shifts in the broader economy, for no one would bother riding such expensive and dangerous pokemon unless carrying truly valuable cargo; any item they transported would be bid up to multiples of its original price. Some merchants who bought these items made fortunes of their own; others found that exotic origin alone was not enough to match the tastes of Paldea's aristocracy, and bankrupted their houses trying in vain to unload their goods. These ruined merchants would gather their own local specialties with what was left of their wealth, and fled their creditors across the desert – on the back of an Orthworm!