This is why when you buy a tea-cup piglet, you need to check into who you’re buying from. The seller should be okay with providing information on its, well, pedigree. A lot of people try selling normal piglets as tea-cups (as seen above). A normal tea-cup will be about a foot tall. Though, as far as I know, there is no guarantee for size even with a good pig history.
That’s not to say a pig isn’t the pet for you—only, it is one of those things you need to look into.