The displacer dragon is an unholy aberration created when an ancient black dragon is infected with the same invasive symbiote that creates displacer beasts and other displacer creatures, as detailed in my Alternate Ecology of Displacer Beasts. Appearing much the same as any other black dragon, it has the same displacement properties as its lesser kin, and tentacles sprouting from beneath its wings.

Sheet here: https://www.patreon.com/posts/109065197