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.
illus. Bram Sees # 031/96