The Shadow Tab is a Don't Starve Together exclusive tab for Maxwell. Here, the player can craft the Codex Umbra, which itself is used to unlock the second tier of shadow crafting, and the 4 different variants of shadow minions.
Crafting shadows will consume Maxwell's maximum Sanity, making the player vulnerable to Shadow Creatures. This can only be reversed when the shadow is dispelled. A shadow that is dispelled by the player who created it (using Ctrl), will refund a Nightmare Fuel.