As a quest objective Edit
- Drops rate is 100% from Azuregos.
- DOES NOT drop from the Cobalt Broodlings in Winterspring.
- It does not Bind on Pickup, so you can buy it from someone else or from the auction house.
- Patch 1.5.0 (2005-06-07): Mature Blue Dragon Sinew can both now drop off appropriate level blue dragonkin monsters. It should be noted that Azuregos will guarantee a drop but to get it from the lesser creatures will be a much rarer occurrence.
- Patch 1.4.0 (2005-05-05): Added.