I just recently got into Terraria (thanks Steam Summer Sale!) and it has been generally pretty entertaining. I am now trying to create a Nightmare Pickaxe but I first need to get enough Shadow Scales to do so. Where can they be found, and what is the easiest way for me to obtain them?
Create Worm Food and activate it in the corruption. Build a nice platform to stand on and kill Eater of Worlds (which spawns when you activate Worm Food). You'll get LOTS of shadow scales.
One easy way is if you have the Demolitionist NPC, you can purchase bombs and blow up Ebonstone to get to Shadow Orbs. Not only can you get a musket (which allows access to the Arms Dealer), sometimes a meteor will land. The Eater of worlds will also spawn so if you don't have worm food you can just break shadow orbs with a hammer. Every 3rd Shadow Orb that you break will spawn the Eater of Worlds.
i killed him using a lights bane and iron armor with some potions to heal and a demon bow with fire arrows. he is not to hard, you just need to keep track of how many there are (if you hit him in half),so that you don't get hit by a lot of smaller ones. if you can kill the small eater of worlds, then it is not hard because he does not do to much damage. i killed him and got 118 demonite ore and a bunch of shadow scales. if you kill the eye of Cthulhu first, and then use his drops to make a lights bane and demon bow. ( make the demon bow first, and then use it to kill him again,so you can make a lights bane) he is not a hard boss if you have potions of healing and a o.k armor. (iron or greater) i had only 120 hp when i killed him and it is not hard to spawn him if you have the driad npc because you can buy the purification powder and use that to destroy the orbs. PS, meteor armor and weapons is worse than demonite Armour and weapons.