So after playing through what I consider to be a hefty portion of this DLC, I can say it's a unique addon to the game. It adds a new element to gameplay using animals to do fetch quests or fight alongside you {I dislike that myself only because I like to snipe and not get involved with close quarters combat}. The pets have quality like items do and can be raised with an item purchased in Town Hall. Most mobs that are animals are tamable using foodstuffs in the form of "capture meat" where it befriends them; used in a similar fashion of throwing rocks.
Pets can be leveled using either the taming items or basic food items {FINALLY YOU CAN GET RID OF THOSE 1,000 MEAT STACKS}. This affects their base statistics and unlocks new abilities in combat. They have friendship as well which unlock either permanent or ally bonuses. There is no need to feed them in similar fashion as mounts and only need to be fed to raise stats or watch their animations.
Their housing comes in several varities. However, the most functional one is the Pet Apartment which holds several pet beds in one small area which is good for load capacity. Pets can forage plants, dig rocks/ore, explore for relic fragments/misc, or general combat over a large duration of a day which yields random stuff. These drops are tied to where you are in the main story. So you won't see Magnesium Ore from Day 1.
The pet currency is earned through one of five ways. Pet combat dispatches, certain milestones with certain pets, releasing pets back into the enviroment {rarity+level are tied into amount}, purchasing the credits at the Town Hall Store, or opening the DLC mail. They are easy to get and sadly don't getcha much beyond cosmetics or useful general pet supplies.
This DLC is a 8.5 out of 10. A decent upgrade to the game base mechaincs where you get to watch a horde of cactus carrying lizards scurry like crazy everywhere or just play "Gotta catch 'em all". If I had to make one sad note, robots cannot be acquired as far as I've seen; so auto -1. If you ever see the DLC on sale; I recommend acquiring it.