The Mad Lady of Hirschorn
From Oberon_wiki
The "Mad Lady of Hirschorn" is not actually a person but a folk-tale about a woman who was so mad that she bet she could drink all of the water in Lake Viridian. The story has it that she tried to drink the lake dry every day for 50 years until her death but, sadly, she was also cursed with a very weak bladder, and hence is said to urinated most of it back into the lake.
The beer know as "Mad Lady" is brewed in Hirschorn - its name (jokingly) implying that it is a weak beer, akin to water.