There is currently an ingame way to tame horses and convert them to mounts via a NPC in the game. It would be very nice to be able to convert a combat pet to a deco pet that you can place on a lot. This would enable you to combine coto store deco pets (tiger cubs) with combat pets (adult tigers). Just a thought.
Not only combat pets. Take the horse from your first expample. When first tamed a player can use it as a deco pet but only one that follows him around as it is tied to the collar it has been tamed on. When converted it becomes a mount tied to a collar. However one can not place the horse in any state on a lot, e.g. to fill one of the ingame existing Stable buildings with one of the existing haystacks in front to feed on...