It's easy to get carried away :-)

You can simply start animations of scale, XYZ location and XYZ angles and then change speed and/or direction of each variable.

You can reverse the direction when reaching the boundaries of the screen.

The butterfly flaps its wings with a quick rotation about its Y-axis.

Flies being what they are, we occasionally flip the direction at random, too.

The 'Adjust Rotation to Direction of Movement' command keeps things pointing the 'right' way.