The Magic Acorn is a Hardmode summon weapon that drops from Treasure Bags when opened in Hardmode. It summons a squirrel to fight for you. The minion attacks by throwing acorns at enemies and charging towards them as well.
Its best modifier is Ruthless. The Mythical modifier provides the widest array of stats bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, minions cannot deal critical hits. The only significant advantage a Mythical Magic Acorn has over a Ruthless one is knockback.