The fishy stick phenomenon began when Captain Eldrad joined the Official Forums on January 18, 2001. The graphic used is from an advertisement for Captain Morgan's rum, with a fish stick in place of the bottle of rum. In the beginning, fishy sticks were only given to those who truly deserved the honor, by Captain Eldrad himself. Later, his friend Soursha gave them away to new members. Eventually, it became customary to give fishy sticks to the newcomers of the forum. The Bethesda developers were very amused by all of this, and they added tributes to the fishy stick in Morrowind, Oblivion, Skyrim, and ESO (see below).
Even though Captain Eldrad and Soursha rarely visit the forums, the fishy stick continues to live on. To this day, newcomers of the Official Forums are given fishy sticks by the more experienced members of the forum. Some say that being given a fishy stick is part of the initiation of becoming a regular member. Others dismiss it, saying that it is simply a fad that will go away in time, and although it has lost more popularity as time goes on, it is still used commonly.
There are a few references to the fishy stick in the Elder Scrolls video game series:
A tribute to the fishy stick can be found in Morrowind in the form of a book called Capn's Guide to the Fishy Stick. It says that the book is supposed to be the definitive reference to fishy sticks throughout Tamriel, but unfortunately the pages are so smeared with fishy stick sauce that it is impossible to read any of them.
Elder Scrolls Online