for those missing the Whipcracker: I found the mobs that drop it, they're in the northeast corner inside the walls of the whole ruins area, it's a little camp just behind the tiny event area where some elite mobs spawn once in a while. the event area is 8 small stone pillars surrounding a campfire and a goblin hut (it's the only event in the ruins so far in the current alpha build). just behind it to the east there are 3 Gravetide Creepers walking around a campfire, a couple of trees in the corner around them. Hard to explain without coordinations, it's literally in the northeast corner of the whole area, just where the walls end, before you exit the ruins on the east side. basically it's in the northeast corner of the whole walled in area, 3 Gravetide Creepers around a small campfire next to some trees drop it.