so this is the pickaxe mole cg. what you need to do in mole dungeon is first talk to this guy, then find his pickaxe and as a reward you can get this cg. You may be given a chance to kill or throw him which you should not do.  I think, not certain though, you need to keep your lockpick for this. there will be so many options where you can use the lockpick but it is only one time use. meaning if you have used it somewhere else, you may not be able to get the pickaxe and get the cg. what i did is saved at the moment of starting exploring the mole dungeon because you cannot roll back.