You control another nontoken creature with mana value 2 or less.
Steps
1Cast Whitemane Lion by paying its mana cost.
2Bygone Bishop triggers twice, creating two Clue, two Food and two Treasure tokens.
3When Whitemane Lion enters the battlefield, it triggers twice, returning itself and another creature with mana value 2 or less from the battlefield to your hand.
4Activate the two Treasures by tapping and sacrificing them, adding two mana of any color(s).
5Cast the other creature by paying its mana cost.
6Bygone Bishop triggers twice, creating two Clue, two Food and two Treasure tokens.
7Activate the two Treasures by tapping and sacrificing them, adding two mana of any color(s).