Weirdomatic.com have assembled a motley collection of weird bass guitars, from alt.guitar.bass , and Ed Roman's Website. Which do you think is weirdest?
Their weirdness scale appears to rely on a combination of strange body shapes (animals, fruit ), unusual finish (furry ZZ-Top style), unusual body materials (Plexiglas), and extra necks or strings.
According to those criteria the weirdest possible bass would be made out of Plexiglas (but with a furry finish), have a body the shape of Texas, with an extra 12 string neck. By my calculations that would give a weirdness factor of 14.7.
The first bass in the list is shaped like the USA. It demonstrates that America is nearly guitar shaped. If you attach the neck to North Carolina, Florida is the lower horn and Maine is the upper horn. If they gave California to the Mexicans and Washington and Oregon to the Canadians, then the guitar shape would be nearly perfect.
Original link at weirdomatic.com