How to get a head to track an empty I've been working on this robot character and I'm trying to animate so that all the body parts float, similar to that of rayman.

The problem I'm having is I can't get the floating head to track an empty, it comes up with a red box when i try.

How can I rig up this figure properly and get it to move around like it is floating?

Blend file here for reference:
https://www.dropbox.com/sh/h0gc9837wnutcoc/AACIO3YAgyFSY7MviS15yyI1a?dl=0

Any help would be greatly appreciated
The following should work:

Add the empty to your scene and position it in front of the head, then select your head object and apply rotation by pressing CTRL+A and select "rotation" from the list:


Now with your head still selected, go to the constraints panel and add a "Track To" constraint, and in the Target field select the Empty you want the head to follow:


Note: You may have to change the axis in the Track To constraint, depending on which way your head is looking. Judging by your screenshot, I suspect it will be something like -Y