(Not to be confused with the Magic Shop. )The potions shop is located in the Dukka Caves. It trades potions for MP. The shopkeeper is a Wizard Chibs.
(Link to shop: http://www.marapets.com/shop.php?id=34)
Most of the stock you will come across will be the standard species of pets with nothing more than colour variances, however, be quick and you may find a rare coloured potion. This is the first shop in Marapets to restock items upto Rarity 40! Obviously, it will only restock items of rarity 31-40 very, very, very, rarely; you probably won't personally ever get to see a rare Limited Edition pet potion restock. But good luck to anyone who ever catches one!