Alchemists orb

This item loves to teleport in inconvenient places and allures magic casters to touch it. If the orb feels the caster has 'earned' it, on touch it returns all the spell slots of the caster. The orb is conscious and acts in a similar way to a child, if it finds a certain caster to be fun it will follow them, somewhat obliviously. 

The item can only be destroyed by +3 or higher magic item and if it feels at risk it will simply use it's reaction to teleport to a safer place, usually a dark empty cave it finds comfortable.