When finding a Wandering Villager, they will be very fast and sometimes break the lead, causing some bugs. The game will make the leads drop 0-2 leads, even though there were two leads. Also, when killing a mob attached to a lead that's connected to a fencepost, killing the mob can create a graphical bug where the lead is still there, floating and connecting. Couldn't get this to happen again. :l Uncommon, but annoying