This would be a greenish worm, available in a level 4 Dark Barracks for quite a bit of dark elixir, that will attack resource collectors in this order- Dark Elixir Drills, then Gold Mines/Elixir Collectors. If it manages to do 25% of the damage to a structure that is destroyed in that raid, it is given a debuff called "leeched", which gives a red tinge to the building. Up to 20% (depending on the leech's level) of the output of the resource collector will go to the player that raided it. This lasts for a day, or the player can remove it for a substantial amount of gold. Only 1 leech debuff can be applied to any given resource collector. If another player destroys it in any way that would apply a second leech debuff, the first leech debuff stays, and the second debuff is not applied. Also, only 3 buildings in a village can have this debuff. Feel free to add on to my idea, but be sure to give credit where it is due!