This plum-sized skull carved from silver is tarnished black.

A talisman of undying fortitude allows you to take on some of the physical qualities of undead. When you activate the talisman, you gain immunity to poison, sleep effects, paralysis, stunning, disease, death effects, critical hits, nonlethal damage, physical ability damage, ability drain, energy drain, fatigue, exhaustion, death from massive damage, and any effect that requires a Fortitude save. Also, you do not need to breathe. This effect lasts for 3 rounds.
A talisman of undying fortitude functions two times per day.

Prerequisites: Craft Wondrous Item, veil of undeath (SC 229).
Cost to Create: 4,000 gp, 320 XP, 8 days.