- Bunny ears
- Large eyes
- Short height (3 to 4 ft)
- Highly intelligent
- Cat like nose
And for the gravity of their homeworld we can assume it's Earth range 0.90 G to 1.10 G, and has a similar environment to present day Earth.
And for the gravity of their homeworld we can assume it's Earth range 0.90 G to 1.10 G, and has a similar environment to present day Earth.
Let's go one point at a time:
Bunny Ears:
There are a few primary uses of bunny ears, with hearing being the obvious function. Heat loss is a secondary function and reason for their size, but it requires a large amount of blood vessels and means they are also highly sensitive. Now it doesn't mean your new creation has to have all of these traits, but removing a trait makes it more difficult for it to occur naturally. For the bunny ears to happen, they need a situation that requires accurate hearing.
Large Eyes:
Even in humans, large eyes are linked to a need for better vision. Larger eyes are generally more vulnerable to damage, so excessive size becomes a negative with the largest eyes primarily being used for nocturnal vision. Larger eyes also assist with collision avoidance when moving quickly. (Credits to Saidoro for the collision info.)
Short Height:
I'm having difficulty finding anything that benefits a specific height. Depending on the diet and how much food they can obtain, your creature may find that height to be optimal, which is not an unusual feat at 3-4 ft.
Cat's Nose: (skipping intelligence for a moment)
This type of nose is highly sensitive, and useful for hunting, eating, and tracking. Much like dogs, it allows for tracking scents and marking territories as well as defending them. It also replaces a lot of the sense of taste and can be used to determine how edible a food is.
Taking all of these together, you're asking for a creature to evolve that has great senses of hearing, sight, and smell, potentially able to be nocturnal as well as very fast. Now if you want it to have intelligence, it needs a reason to develop it. As Cobaltduck mentions, either being hunted or being a hunter can provide that stress if the other is intelligent as well. The ones that best adapt to staying alive will survive and reproduce, as is natural selection.
As of now, i can't find any creatures that resemble what you're looking for. There's some weird stuff in Africa, but nothing large enough that has all the traits. So, you'll need some kind of stimulus to push one of those things to develop some brains. Considering it's not perfectly clear how we developed our intelligence anyway, you can take your pick.
Bullet points one through three in the question bring to mind an existing animal, the wallaby. (Note: this was originally written before the question was edited to add cat nose as a feature. The comparison between wallaby nose and cat nose is debatable.) That just leaves number four- The wallaby is already slightly intelligent, why would it become highly intelligent?
We need one or both of two things- something it preys on, or something that preys on it, that is itself somewhat intelligent. The wallaby and this other creature cycle each other in an evolutionary arms race- putting pressure on each other to identify the best spots to hide and ambush, to cooperatively hunt or keep watch, even to create tools.
What results will be either a really awesome pet, or something you don't want to meet up with on dark night.