transform.lookat in 2d code example

Example 1: 2d object look at object

Vector3 dir = enemy.position - transform.position;
float angle = Mathf.Atan2(dir.y,dir.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.AngleAxis(angle, Vector3.forward);

Example 2: unity look at 2d

transform.right = target.position - transform.position; // Works like a CHARM.