Pets

* See also Player Residence
* See also KittyCatsInRapture
* See also Sea_Slugs
* See also Other_Denizens_of_Rapture
* See also Rapture_Society
 A Cat from : Red Dead Redemption 2 ( a 2018 action-adventure game )
With Improvements in Graphics and game CPU/Memory capacities, the various animals can be more than some static object used over and over.
Interactive Pets would be in the MMORPG.
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Pets For Players :
Useful Ones that live in your Residence or Store/Shop/Business ( some have some utility - like Vermin Control ).
'Pets' that might accompany you on Expeditions ? -- There are (complex) Behavior Programming/Scripting and Animations (lotsa game development work) issues ( There would be trouble enough making Splicers/NPCs behave correctly/intelligently in situations -- This wouldn't be pre-canned/"Here Booker Catch" simple stuff ).
The obvious surviving Cats unfortunately don't like to be herded. ( But they (generally) sit home just fine as long as you feed them regularly, and can keep down the rodents and bugs there ).
Robotic 'Pets' may have been all the rage at one point in Rapture ( later, right before that 'civil war' thing threw the whole of Rapture into chaos ). Their mechanical limitations would make them less unpredictable in their actions ( and limited 'smarts' would have them be little more than lame toys ).
'Training' Advancement Ramp for Pets ( means also communications of commands (interface) for them ). Sorry, dressing your pets in cute clothing will earn you a trip back to the Sanatorium.
If you make the scripting of autonomous Pet behaviors then Pets For Splicers too ...
* Cats
* Rats ( White mice from the old medical areas probably didn't survive very well )
 
* How many Dogs would be left ? (they're good eatin' ... )
* Fish tank (Sea Slug ?) 
* Pet Sea Slugs to generate ADAM ( implanting them ist Verboten ). Unfortunately THESE are very rare, as they were depopulated in the vicinity of Rapture in years past.
* Roaches (for racing)
* Barnacles stored in an aquarium/jar ready for late night snacks aren't exactly "pets",.
* AND Other things Player Creators will no doubt create.
* Would there be Dogs any more ? ( They are more edible in general than Cats ).
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Birds in Rapture :
As Pets ( Problem - Many don't breed in captivity ).
Getting loose/feral/abandoned :
* Closed/Partitioned interior areas hampers them
* Their getting food being a problem
* Avoiding predators/vermin (rats love bird nests)
* Crapping all over the place (public nuisance)
* Cats love the taste of 'Tweety Birds'
* ADAM contamination may produce some interesting mutants 
* At Least one Dead Parrot for two Splicers to be discussing ... ( a Norwegian Blue possibly A whole Splicer Rant about a Parrot that Andrew Ryan was supposed to have owned - going on at great length and becoming as crazy/obcessed as some ridiculous online forum discussions. )
Heh - ADAM might make them look like miniature Songbird ("Pigeon in a Gimp Suit") to delusional Splicers. We did see more than one birdcage in the original games .
Chickens are birds (duh). There would have been numerous 'farm' animal (livestock) birds. They grow fast when 'factory' type methods are used, and are an efficient method of making 'meat' for Rapture inhabitant's meals ( as well as the egg production ). I suppose there would be turkeys and geese originally brought in, but few probably would be left by the MMORPG's times ( except in stable enclaves ). 
An Opportunity for someone : Pet Chickens ... 
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Frogs and Toads For 'Licking' :
Hallucinogenic toxins on the skin of various Amphibians ...
Hmm ... Sounds like :
* Something which would 'fit in' Real Well in Rapture ( freedom for drug use made evident in-game ).
* The whole of Columbia has such substances contaminating its Water Supply ( perhaps purposefully by Comstock ).
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Advancements in Computer Gaming Cats seen in "Red Dead Redemption 2" - have allowed much greater realistic rendition. Cats that are ALIVE, and act somewhat like 'Cats' ...
I would not doubt that, with the interest Players would have, that the Cats and Dogs might be made some of the most sophisticated animation/behavior Objects in the MMORPG.
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Posters like this indicated that Pets DID exist in Rapture
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