One of the latest quests added with the patch 10.0.5 for WoW Dragonflight requires you to find Happy pet Snacks.
Happy pet Snacks are items that date back to the time of World of Warcraft Wrath of the Lich King. So you'll have to visit Dalaran and buy the Happy pet Snacks from Breanni. Note that this NPC is available in both versions of Dalaran, Legion and WotLK. The latter is in the Menagerie, just to the left when leaving Krasus' area.
If you have a Dalaran Hearthstone, you can use it to reach the city as quickly as possible. Otherwise, you can take the Valdrakken portal to go to Dalaran.
Once you're inside, you'll find the little gnome right in front of the counter. Open the chat window and buy your Happy pet Snacks.
You can then give your treats to non-combat pets. It is clearly specified that the familiar must be peaceful. Once your challenge is complete, you can collect your Coins and continue your farming!