Farnsworth's grandmother

Farnsworth's grandmother is the mother of either Ned or Velma. Farnsworth owns two of her former possessions, the diamond filament tether and the jar of a cranberry-raisin typhoon.

Trivia

 * She's probably deceased, considering the Professor is 0 years old, and that he talked about her in past tense in "The Deep South".
 * It isn't confirmed if both grandmothers referenced are the same person.