Sugar pigs hold sugar and are great to have for those guests who wish to sweeten their coffee,tea, etc...
I suggest you look online using the more common term "sugar bowl."
I don't know the origin of the term "sugar pig" but doing a quick search both on Amazon.com and Google indicates the term clearly is not commonly used.
Wow they are hard to find. If you Google it, then look at images. Scroll down and you'll see a picture of two pottery sugar pigs with a cork in their nostril. The website is visible if you click on the photo. They are listed at $15 each. Apparently that is also a breed of tiny pigs. Enjoy the photos.
I am not familiar with sugar pigs. You could instead use a salt pig. Salt pigs are very common and readily available online in a large variety of sizes and colors. Search "salt pigs" and you will find many sources for purchasing online.