Cat disappears when I go to sleep

I told one of my cats to stand up so that when I went to sleep, they would hopefully bring me rabbit hide so I could make leather for an enchanting room. When I was going to sleep, it worked like usual, where the cat came up and laid down on me. However, when I woke up, it just magically disappeared. When I went down into my mine later, it teleported to me. I was really confused because I didn't see it come down with me.