As revealed on Twitter via the official Dark Souls 3 handle, a special Estus Flask will accompany the hardcover guide of Dark Souls 3 upon purchase.
The flask is a “high-quality, resin replica”, and mimics itself on the real game item that allows players to regain some HP.
This special bundle will only be made in a certain quantity, and once the quantity is sold out, no further bundles of this kind will be made. You can pre-order this through the Gamestop website here.
Dark Souls 3 releases April 12th.