Acid Resistant Fishing Rod
You can get it by doing Buried Cathedral mission in The Dream Courts Quest (You have to click on pile of rubbish to get it). You need Acid Resistant Fishing Rod to find the first word (K'muuh).
Mechanical Fishing Rod
You can get it by doing Just A Fishing Trip mission in The Isle of Evil Quest from NPC Rapanaio. He wants you to fish a Mechanical Fish from the sewers of Yalahar, a fish you can only catch by using Nails as bait.
Fishing rods are used to fish (a fish you can only catch by using worms as bait). The more you use a rod, the higher your fishing skill becomes. Only some squares of water contains fish at any given time, and once a fish is caught from a square, it will take around 30 minutes for it to respawn. Fishing is the only skill that is not related to combat.
Simple Fishing Rod
With worms in your backpack you can use as Simple Fishing Rod to try to catch Tiny Bas (Orcsoberfest).
Stout Fishing Rod
With Tiny Bass in your backpack, you can use it as a Stout Fishing Rod to try to catch Small Bass (Orcsoberfest).
Advanced Fishing Rod
With Small Bass in your backpack, you can use it as an Advanced Fishing Rod to catch Bass (Orcsoberfest).