Staff of the Ivory Claw

From Explorer's Guide to Wildemount, page 270.

Description
Staff, rare (requires attunement by a spellcaster).

This gray-and-cerulean staff is topped with a small dragon claw carved from ivory. While holding the staff, you gain a +1 bonus to spell attack rolls. Whenever you score a critical hit with a spell attack, the target takes an extra 3d6 radiant damage.