Acornelia, Fashionable Filcher

Oracle Text

Whatever you cast a spell with a squirrel in its art, you get [A] (an acorn counter).

Whenever a Squirrel you control enters the battlefield or dies, you get a [A].

2B, Pay X [A]: Target creature gets -X/-X until end of turn.

G, Pay X [A]: Target creature gets +X/+X until end of turn.