Merchant Ghost

Overview
The Merchant Ghost is a non-hostile mob that has a chance of appearing near a shop on any level that has one(with the exception of the sanctuary). The merchant ghost has a 100% chance to drop a random schematic when killed.

Behavior
When spawned, the merchant ghost will idle around the current level's shop, moving about occasionally but always staying near the shop. This behavior only changes when approached by the player. Once the player is close enough, the ghost will attempt to flee, moving in a random direction away from the player. The ghost will do this regardless of whether or not the player attacked it. Despite being a ghost, walls and other objects that would normally stop the the player will stop the ghost as well. This can be advantageous, as the ghost is quite fast and the player has a limited window in which to kill it. If the player fails to kill the ghost within several seconds, the ghost will disappear.

Drops
Schematic