"Fast, spindly, human-sized combat mechanoids. They usually carry one primary ranged weapon, and their bodies are adorned with two articulated blades to make them deadly in melee combat. They don't use cover. Best handled by concentrated, overwhelming force."
Scythers are a type of fast-moving mechanoid with strong melee skills that can be found sealed in ancient ruins in all biomes, either spawned inside mountains or outside on the landscape. They may also raid the player's base through a random raid-type event and can also be found in most poison ships and psychic ships. Scythers are often supported by centipedes.
Like other mechanoids, scythers are sentient machine-like creatures which do not need to eat, cannot be tamed or trained, and are always hostile to the colony. Scythers have a moderate resistance to sharp damage and a small resistance to blunt damage combined with an average health scale, making them trivial to disable at range with sufficient firepower. If you don't have very good long range firepower, it's better to try and get them into close quarters ranged combat due to their limited durability and because their superior long range firepower will be redundant at this point. Scythers are vulnerable to deadfall traps, with only a few hits required to kill them.
Scythers will always spawn equipped with the charge lance and will generally prefer to engage at range over melee. However, they are horrifyingly effective at melee, being the enemy with the highest melee DPS in game, surpassing that of the Thrumbo.
Downed scythers can either be killed by directing a recruited colonist to fire/melee it until it is dead, or can be shut down by adding a medical bill. Shutting down a scythe will negate the opportunity to remove their parts, otherwise allowing you to harvest up to 2 Scyther blades as long as the blade parts are not damaged or missing. Dead scythers may be disassembled at the machining table for 40, 25, and 1, though these values are affected by mechanoid disassembly efficiency.