My Happy Ghast and cat disappeared

My Happy Ghast disappeared, I go into my saved game and see that my Happy Ghast is missing, At that time I had the block load at 128. Something similar happened with my cat. I was on my Happy Ghast. At that moment, the block charge was at 1 and after moving away a bit, it disappeared. I assumed it was normal because it had that block charge, but I save the game and when I come back, the cat is not there.