I created a new world for testing the upcoming changes using minecraft 1.7.10.

In that world in creative mode, I used a spawn egg to produce an ocelot. I then tamed the ocelot so it became a cat.

I told the cat to sit down.

Then I copied the world over to my snapshots save folder and opened it in 1.8 pre release 2.

Now every time i click on the cat or baby cat to tell to sit down, it generates more cats in the same location.

I did not expect cat entities to duplicate when telling them to sit.

Edit: I created a new world using the 1.8 pre release 2 and spawned in an ocelot and tamed it and told it to stand and sit repeatedly, but I cannot get new baby cats to spawn like I did above.