As in instigator. Instigating posts made intentionally to piss you off. Not to be confused with trolls and their damn trolling, gator posts are done by someone PRETENDING to be against something. A gator touches a keyboard to push buttons for control of your mind or a thread.
Something or someone of exceptionally high quality, most commonly spoken from the mouth of a gator. (See definition for gator- i.e. "best pimp in the game")
Rather than a straight and symmetrical rail of blow a "Gator Line" is best represented by the increasing and divergent width of an alligator's tail starting at the tip and proceeding to the more dangerous main body. Hence the increasing excitement and danger of the Gator line.