After you pick up the quest you need to do the following to finish (SPOILERS!)
- Talk to Maru again. There will be a few options you can say, but based off the stolen toys being a ball and a plushie, the most likely suspect is a dog, so mention that to Maru.
- Maru will tell you (Horde side) that Nuts lives near big animals, so go back to Dazar'alor.
- Talk to Matan next to the squirrels. He will mention that Nuts was chased by a big animal and that you should take a look where you found the previous toy.
- Head back to the tree next to the waterfall where you found the plushie during the previous quest to find a Bakar Sketch next to it.
- Go back to Maruukai in the Ohn'ahran Plains.
- Find Getseng close to the main building and talk to him. He will tell you one of the Bakar pups has been getting into trouble and that he's hiding "under Ohn'ahra's watchful gaze".
- Go to the mountain next to Maruukai where the big statue of Ohn'ahra is located. At the very top of the mountain, next to the statue and Ohn'ahra herself, you will find a chew toy. Grab it.
- Next to the chew toys are some Teerakai Burial Bones, which means we need to head to Teerakai next.
- Go on top of the mound in the middle of Teraakai to find a Toy Box. Put the chew toy in and hide in the bush next to the box (you need to right click on it and nobody else must be hiding for it to be usable).
- That will spawn the Bakar Pup. Follow the pup to a cave where you will find a pile of toys. Among it you will find Maru's toy. Grab it and bring it back to Maru to finish the quest.