There are no RPG games that has no in-game pets. When I first started to play this game. I'm always excited on the drop materials. Waiting if the Hunter will not going to pick it up automatically. Just to complete quests and expecting to drop the materials that I need to from a weapon, armor or even jewelry.
Okay! So, lets see this clearly.
If you want a pet to help you to loot an items for you, then a Pig or Kitty fairy what you need.
And the adopted pets will be a assist you to boost your Town buffs.
Simply go to Shop > Gem > Fairy & Pet.
Pig and Kitty fairies
Both glittering small Pig and Kitty fairies, will follows one hunter around to collect materials and give it to you directly. In addition, the hunter will also increase 10% more Gold while farming. (I laugh sometimes when the hunter says "Hey! that's my loot!" to the fairy).
The Adopted Pets
After you adopt them, you will see these pets around. They seems like beautiful decoration to your town., but these provide additional buffs.
As you can see, below image is the current active buff that I have in my town. This is effectively applied to each hunters. When I started to have the Vampire bat, it is already a big help for me since I am a main Berserker. Also good in both of my Legendary Rangers. Then I decided to complete all five pets first because the use is not only for individual hunters. see image below of my active buffs.
Vampire Bat - a bat gives your town 5% lifesteal, for a maximum of 2 bats total of 10%.
Dark Fox - a fox adds 3% of your town defense, for max of 2 fox total of 6%.
Baby Dragon - this will hand you more power. ATK 6% plus! Limit only for one dragon.
If your not a spender, don't worry. There are ways to earn free Gems here in this game. You just need to be patient to do it everyday.