Source: Tales from the Yawning Portal

Wondrous item, rare (requires attunement)

While you wear this amulet of silver and turquoise, you have advantage on saving throws against effects that turn undead.

If you fail a saving throw against such an effect, you can choose to succeed instead. You can do so three times, and expended uses recharge daily at dawn.

Each time an effect that turns undead is used against you, the amulet glows with silvery blue light for a few seconds.