When this user was younger, they had a contest with their friends to see who could catch the strongest Excadrill in one of the Gen V games. Unfortunately for them, they only managed to catch the third strongest Excadrill. This resonated with them so much that when they decided to make a Smogon account years later, they thought of this contest from way back when and were inspired to use their result as a username. To keep things ambiguous, though, they opted for "ThirdStrongestMole" rather than "ThirdStrongestExcadrill".