The Pet system allows characters to summon animals to aid them on certain tasks. Most pets have to be bought with Silk, or Silkroad's private currency on the Item Mall; however, the Grey Wolf can be bought with in-game gold.
Pet Myowon (Monkey), Pet Seowon (Squirrel), and Pet Toto (Rabbit) can be set to pick up items dropped by monsters, and are only available by being bought using Silk. They have their own inventory and save time by doing this task automatically. However, these three pets are only rentals, usable only for 28 days before becoming unusable. When the time limit runs out, the pet is automatically returned to the players' inventory; there is no chance to remove any items left in the pets' inventory. However, it is possible to regain usage of these pets via the Silk item 'Revival clock', which prolongs the rental period by 28 days.
White Wolves and Grey Wolves are combat oriented pets, possessing their own statistics and gaining experience from combat. They also have the ability to grow, beginning as a puppy and maturing into a full-grown wolf at level 40. Both Wolves are permanent additions; once bought, either for Silk or for gold respectively, they do not disappear. Wolves can, however, die during combat and that will make them unable to be summoned. They can be revived with the "Grass of Life" herb sold at each city's Stable NPC.