Blood Drinker was a greatsword that both dripped and drank blood. Originally owned by Trant Thumble, Tum "Darkblade" Thumble was assigned by the Darkblades to steal it as an initiation. When the then un-named Ätlän-tã Fælcons found Blood Drinker, it formed an immediate connection with Thom the Dragonborn, who almost didn't give it up. Blood Drinker and Thom vowed to meet again one day and the Darkblades gave the sword to their buyer,Shade Baylish.
At last we heard Trant had tracked down Blood Drinker's buyer and was besieging the buyer's fortress. It seemed likely that he will get his sword back soon.
After coming back from The Crypt of Sinu the Red, Thom the Dragonborn teamed up with Watari and Wren to steal the sword back. They succeeded and for quite a long time, Thom and Blood Drinker were inseperable. It was not until The Battle Above the Abyss, and the death of Thom, that the two finally were parted. Thom's last request was that Jaela, who wanted the sword for herself, chose between it and her very own Pegasus, Princess Ivy Bluemoon. She chose PIBM, and was made to cut off Thom's dick with Blood Drinker, as it was the only thing stronger than Blood Drinker. Both instruments were destroyed down to the hilt. Thom's adopted son, Bucky, kept the hilt, and Thom's petrified tail, to hang on his wall in Deephome.
Blood Drinker does 3d8 points of damage. Period.