The True Gritharvollr is a Hardmode trap sentry weapon.
All spikes ignore enemy defense (except those with at least 1000 defense) and deal half damage to worms. Unlike most spikes, it has knockback.
Its best Modifier is Ruthless. The Mythical modifier provides the widest array of stat bonuses, but these primarily affect the initial summon rather than the sentry's damage. Additionally, sentries cannot deal critical hits under normal circumstances. The only significant advantage a Mythical True Gritharvollr has over a Ruthless one is knockback.