Gormagon seems to be in the news. The definition of a Gormagon actually comes from a piece of doggerel poetry from the 18th century:

A monster with six eyes, three mouths, four
  arms, eight legs, five on one side and three on the other,
  three arses, two tarses, and a c**t upon its back;

Quite what a tarse is I’m not sure but  a Gormagon is in fact a horse with a male and a female rider on it. The female will be riding side sadle, giving the unequal number of legs on each side.