It is part of the October 16 2012 DLC
Does season pass unlock Gaige the Mechromancer?
No, the Borderlands 2 Season Pass does NOT give you the Mechromancer. You only get her for free if you pre-ordered. Those who did not preorder, however, will still have a chance of buying the DLC.
If you are new to Borderlands or to shooters in general, spec in the Best Friends Forever tree, which was designed with newer players in mind.
Experienced players should choose the Ordered Chaos tree.
all special skills that give D374-TP new moves change his apperence
when Gaige has 1 or more stacks of anarchy meleeing will make her slash two times with digi claws like D374-TP basic move consuming 1 stack of anarchy, The more anarchy stacks you have the more melee damage you deal