Help in after effects panning with a puppet from Ch

I am panning a view from space to the ground in a long vertical canvas done in photoshop. I have the panning complete by just changing the y position from the top which is outerspace to the bottom the ground. My puppet remains in the scene starting in space to the ground. I am trying to keep him at the ground only to be revealed when I arrive. I attempted to use keyframes to keep him near the bottom and pop up just in view as our camera view approaches the ground but he does funny things like bounce and it is fairly hard to guess where to have him "appearing on screne" that looks normal. I am sure there are different methods and would love to hear from the community on this.