Big rock alien

The big rock alien was an inhabitant of Neutopia. In June 3011, it encountered a group of Earthican people among which was the Planet Express crew and - confused by the concept of male and female, because the members of his species are solely nuchachos - both neutered them and altered their genders. The alien was disintegrated by Zapp as it was about to return the Earthicans their genders.

Trivia

 * While its name is never revealed, the Borax Kid, a rock alien whom it once made a bet with, once referred to it as "the other rock alien".