FWIW, glFog is deprecated in later versions of OpenGL.
Also can you be more specific about what you want? Do you just want an object to scroll in from the side of the screen? Or start far away from the camera and move closer? Or "appear out of thin air" like it was being teleported with a star trek teleporter? Or fade in from a solid color? Or what?
The idea behind basic animation is you move an object slowly over a period of time.
Give your object a velocity. Every update.. add its velocity to its position. Then set its velocity to 0 when it's at the final position you want it to be.