From Blaseball Wiki
Nightshade is the New Hampshire Eggplants' Evolution Modification. It was first seen following the Season β22 Elections.
During Night weather, a team with this modification will have its hitting and pitching stats improve for batters and pitchers respectively.
As a result of the Library, the New Hampshire Eggplants were revealed as having joined Ultra League Blaseball during Pre-History I, which also revealed their roster and Team Modifications to the Fans. At some point, the Eggplants earned 3 Championships and Evolved, advancing their players to Base 1 , and granting their team the Nightshade Modification.
As of the end of the Expansion Era, it has never been an active Team Modification.