Leveling in carppenters landing off flytraps and I got one of these. Horrible drop rate. So that is about 1 out of 35 killed dropped it. Thought that it was a quest item, well at least i can give it to a freind that is 70 in alch.
The drop rate for these are horrible (even with TH2). If you've ever tried to farm spider webs in Korrolka Tunnel than you know what I mean. Not sure what enhances the drops, but even in a New Moon, they rarely drop.
Perhaps they changed it when they patched drop rates of some items right after the expansion came out, but the drop rate on this is NOT decent without or with TH. With thief sub, 5% tops, not worth your time.
Both forest and sabertooth tigers available in carpenter's landing though, depending on your entrance and elemental spawn points are close together for when there's thunderstorms so it's not the worst spot you could farm mid levels.