Shade
The Shade is a hostile creature form Lycanites Mobs that spawns in the dark. These creatures also sometimes spawn like Grue can, appearing from the shadows when the player lingers in the dark for too long.
Spawning
Shade can spawn in any Overworld biome, or in The End. Can only spawn underground (y ≤ 50).
Shade spawners can be found in Template Doomlike Dungeons, Urban Doomlike Dungeons, Shadow Labyrinths (Lycanites Dungeon) and Dungeons (Vanilla).
Shade can spawn if you spend too much time in a low light area.
Variants
For every Shade that spawns, there is a 10% chance for it to be an Uncommon variants. Uncommon Shades can be Keppel or Russet. A Keppel Shade is a Dark Greenish color, while a Russet Shade is a bronze color. Uncommon shades have double the Health of a regular Shade. This does not change their behavior.
Behavior
Shades spawn in darkness, and will attack any player close to them. Shades are fast, dealing 3 damage per hit, and will also give you the decay effect if you are hit.
Since shades are fast, you can't run away from them. However, Shades are very slow swimmers, so a viable tactic would be crossing a river to get away. If you have a water bucket on hand, use it to slow the Shade down before turning around and hitting it with your strongest weapon while keeping a distance away. Shades have a lot of health, so it might take a few hits.