First appearing in the manga version of Dragon Ball Super, it is a black, silver, and purple-colored power-up form achieved by Frieza after he trained for 10 years inside a Room of Spirit and Time on a planet he conquered. Not only is this form very much superior to his Golden Frieza form, it is also powerful enough for Frieza to easily defeat both Ultra Instinct Son Goku and Ultra Ego Vegeta in a single blow.
This tag implicates frieza (learn more).