Animal Rescue - NWN Side Quest (Chapter 1)
The Great Tree: Animal Rescue begins by speaking with Nyatar in the City Core map. You can find Nyatar by The Great Tree in the middle of the zone, it's marked on your map so it'll be hard to miss. In order to get this quest from Nyatar you'll have to convince him to talk to you about his problems and you'll have to care about the animals.
For this quest you're tasked with heading to the Neverwinter Zoo which is in the northern portion of the Blacklake District. Here you will have to defeat the head honcho of the Zoo and setup a portal for all of the animals to escape through at the Great Tree. Once that's done you'll have to lead/encourage all the animals to go to the portal and take it to Nyatar.
Below is a step by step list of exactly what you have to do in the Zoo in order to complete the quest. If you need more information about any of these steps check my write up below.
How to Complete Animal Rescue:
1. Use your Transport Via Plants Scroll on the Great Tree in the Zoo's Courtyard
2. Defeat the Master of the Pens and use the Lever in his room to open all the cages
3. Speak to every Animal in the Zoo and tell them to leave
4. After freeing all 4 Animals return to the Great Tree and talk with them
5. Tell each Animal to go through the portal then return to Nyatar to complete the quest
Once inside the Zoo you'll have a couple of things to do, the first thing you'll want to do is visit the Great Tree and use your Transport Via Plants Scroll on it to create a portal. As for the second thing on your list, it should be to clear out all of the enemies in the building. In the central portion of the area you'll find someone named Master of the Pens and next to him will be a Lever that you can pull.
Using the Lever next to the Master of the Pens will open all the animal cages but not free them. In order to actually free them you'll have to go to each animal and talk with them and encourage them to go to your portal at the Great Tree. Once you've spoken to all 4 animals use your Stone of Recall to return to the Temple of Tyr in the City Core and speak with Nyatar again to complete the quest. You'll be rewarded with gold and EXP.