Incorporeality

5th-level transmutation

Casting Time: 1 action
Range: Touch
Components: V, S
Duration: Concentration, up to 1 minute
Class: Bard, Cleric, Druid, Sorcerer, Tamer, Warlock, Wizard

You touch a willing creature, causing it, and everything it is wearing and carrying, to become translucent. At the start of each of the target’s turns for the duration, it can choose to become incorporeal (no action required) until the end of its turn. While incorporeal, it has advantage on Stealth checks; it gains resistance to nonmagical bludgeoning, piercing, and slashing damage; and it can move through other creatures and objects as if they were difficult terrain. If the target ends its turn inside an object, it is shunted to the nearest unoccupied space, taking 1d10 force damage for every 5 feet it is shunted.

At Higher Levels. When you cast this spell using a spell slot level of 6th level or higher, you can choose to increase the spell’s duration, or the number of targets, for each slot level above 5th If you choose duration, the duration increases in increments to 10 minutes (6th level), 1 hour (7th level), 8 hours (8th level), or 24 hours (9th level). If you choose to increase the number of targets, the number increases by 1 for each slot level.

Source: Heliana's Guide to Monster Hunting