Character appearing slightly above terrain

If I place my character directly on my terrain and move, he appears ever so slightly above the terrain. As my game is a side scroller, this is very annoying, as it means you are slightly taller than the enemies which are meant to be exactly the same size as you.

This is possibly skin width if using a character controller. In any case, just adjust the position (and height) of the collider in the collider component in the inspector.