Budget Buzzkill Portable Trap - Skinny-mini

Once this trap had a noble name, but someone along the way nicknamed it "Budget Buzzkill" and it's fate was sealed. This brutal and deadly trap remains indistinguishable from the surface where it's located. Once triggered, the blade spins at one thousand revolutions per minute and blurs 40 feet along a path before once again becoming hidden in its original spot.
While inactive, the trap becomes a five foot long rod, allowing for maximum portability. Once placed on a level surface, the bearer need only speak the command word, and within six seconds it can merge with any level surface, becoming nearly indistinguishable from its surroundings

Utility

When activated this 5ft metal rod melds with a level surface along it's entire length. The speaker specifies a magical or mundane trigger along with a direction. When triggered the spinning saw blade will appear to be half-submerged with it's surface and move in the specified direction, even moving up walls and around corners. Any creature in a square along it's path must make a DC 15 Dex saving throw or take 10d6 magical slashing damage or half that on successful saving throw. No trace of the blade's passage is left and at the beginning of the next round the trap resets itself using the same trigger condition and path of movement as before. 
The spinning blade will be immediately destroyed if it comes into contact with an immoveable or unbreakable effect, for instance a wall of force spell.

Manufacturing

4 ingots of adamantine (1,000gp ea)
Powdered Blink Dog Bone (1,500gp)
6 days of construction

Requires DC 15 Dex save to take half-damage
Can only be spotted with DC 20 Int Investigation or Windows Perception check
Disarmed after spotting with Thieves Tools DC16

Inventor(s)

Skinny Mini Website
Artwork by Angel Alonso Miguel

Access & Availability

Once fairly common and cheap, the materials for this trap have become scarce with time. As such, most trap makers avoid it due to lack of profit. Therefore, while it might be encountered within the world, it's almost never available in markets.

Discovery

Subscription club for Skinny Minis in the Dungeon Terrain 2.
Skinny Mini Website

Experience Points:
500

Note: Artwork and Description from Skinny Minis within the Dungeon Terrain 2 set via the monthly subscription. Skinny Mini Website