Heavy Clefthoof leather (drops more frequently off bulls and aged) - Nagrand
Cobra Scales - Shadowmoon Valley, Coilskar
Knothide Leather - just about any beast
Send your knothide leather scraps to a guild leatherworker to transform into knothide leather or heavy knothide leather.
5 knothide scraps = 1 knothide
5 knothide = 1 heavy knothide
Check your AH to see if the conversion is worth it. It was on mine. I was able to make 900gp in 2 days in Nagrand and Shadowmoon.
Note: Don't throw trash away! Many of those stacks sell for 2g to vendor! If a green drops that looks worthless like "of the whale", have a guild enchanter DE it and sell the mats, if something ends in "of the bandit" you will do better my selling it in the AH. Oh, and get Auctioneer!
Good luck!
Edited, Feb 23rd 2007 4:15pm by Ravenblud