A cool glitch for getting hamdrax is to talk to the wizard npc (rescued from the underground after beating the wall of flesh) and buying a music box from him for 10 gold.
You then take the music box to either end of your world and equip it while the Ocean's theme music is playing. Eventually, the music box will change colors and record the track, and change to Music Box (Ocean).
You can then place the music box anywhere, then simply break it. It'll glitch out and drop a hamdrax instead of the music box!