I did a quick search of the forum and found this thread:
https://forums.storm8.com/showthread...ays-timer)-IOS
The pets are the Pumpkin Puppy and the Witch Kitten both of which just drop the normal cat/dog drops like milk and bones but feel free to check out the full list of drops in the HUB Inventory.
I will note that the goals are not the only way to acquire these animals - they're usually added to the Baron's Tent around Halloween or on offer in sales around Sept/October. So I think this goal is only necessary if you're a huge fan of Halloween, cats or dogs; otherwise you'll likely be fine waiting until the actual holiday to get these items.