Minecraft Dungeons:Wraith

Wraiths are undead hostile mobs found in certain levels in Minecraft Dungeons

Spawning
The Wraith can naturally be found in the Highblock Halls, Cacti Canyon, Fiery Forge, Obsidian Pinnacle, Soggy Swamp, the Underhalls, the Creeper Woods and the Overgrown Temple It can also spawn naturally within the Desert Temple and the Lower Temple but is usually summoned by a Necromancer.

Behavior
The Wraith attacks the player by creating areas of scorching blue flames on the ground that burn the player and cause significant damage over time.

Stunning the Wraith while it is attacking allows the player to cancel its attack.

The Wraith can teleport away from players and their own path of flames to avoid taking damage.

Trivia

 * The blue flames the wraith summons appear to be soul fire. Minecraft Dungeons was announced, and in development, quite some time before the Nether Update and soul fire were announced, however.