In this feature, it will require multiple drops from multiple mobs.
First off, to get this feature started, I believe that spiders should be able to drop string.
Next, I believe that the sticks dropped from mushrooms, or bought at shops, along with the string dropped from the spiders, could be used to craft a better fishing rod. This should be a quest given by the fishermen, for when you reach a certain level of fishing, which is going to be added today or tomorrow (the thing being added being levels of fishing).
This would be good for the game because it would expand the gear for fishing, thus causing more people to participate in it.
What other ways do you guys think we could obtain fishing rods?