What is Rock Lobber?
1.
a person who resides in Iraq and likes to throw rocks at vehicles, and other moving objects
This rocklobber is denting up my tank
See
2.
an individual fucked up in the head so much that he assumes a stone or pebble is able to render a tank or other heavily armoured vehicle immobile.
The rock lobber assumed his skipping stone would penetrate the 8 inch thick armor of the tank