Board Thread:New on Gravity Falls Wiki/@comment-33324521-20180618010808/@comment-37343442-20181029180712

I think Bill is back as a blackbird because when he was "dying" he invoked the name AXOLOTL so he could return as another form. Afterwards, Bill became a statue with his right arm extended as to shake someone's hand to strike a deal. Later on a blackbird landed on Bill's right hand and then went straight to the Mystery Shack and looked into Mabel and Dipper's bedroom.