How to get Eltonbrand - Elder Scrolls: Morrowind
Requirements: Be a Vampire, obtain Shashev's Key and hold exactly 11171 Gold
Eltonbrand is a unique meme weapon in Morrowind which can only be obtained if the player is a Vampire and they've completed all the other prerequisites. In order to get your hands on this weapon you'll first need to obtain the Goldbrand which is a powerful and somewhat easy to get Long Blade. For more information on how to obtain Goldbrand follow the link.
Once you have Goldbrand the next step is becoming a Vampire. To do this you'll need to let a Vampire enemy attack you until you contract Porphyric Hemophilia. If you cast a Weakness to Common Disease debuff on yourself you'll make it easier for this debuff to land on you. Once you've been infected you will need to wait 3 days then rest after which you'll become a Vampire.
Note: You will become 'related' to the bloodline of Vampires that infect you. If you plan to stay a Vampire for awhile and complete some of the Vampire only quests you may want to plan ahead and figure out which line of vampires you want to be infected by. For more information about all of this check out the UESP Vampire Guide.
After you become a Vampire the next step is obtaining Shashev's Key; you can pick up the Shashev's Key quest from Sirilonwe if you desire but it isn't required. You'll find Shashev inside of the Ald-Skar Inn in Ald'ruhn and he'll drop the key regardless of whether or not you're currently on the quest.
With the key in your inventory the last thing you need to do is drop some gold on the ground until you have exactly 11,171G in your inventory. If you've done everything correctly you'll see "Go to Hell,Carolina!" after turning in the quest and you'll receive the Eltonbrand weapon.