There actually the same species?

They both need to wax their upper lip?

One person provides the voice for both

They are both muppets.

My guess ..without cheating and looking it up is going to be that they share the same voice..or rather the same person does both their voices?

http://www.youtube.com/watch?v=c9RfjEsEUnU

A gravelly voice..other than that, zero, nada, zilch, bagel..:)

Easy - they were college roomies... :P

The voice of Frank Oz . . . I can't watch the Yoda fight scene without thinking "Super Grover/Yoda!"

they both work with a hand shoved up there ass

Frank Oz's voice. "Oz is known for his work as a puppeteer (including voices), performing with Jim Henson's Muppets. His characters have included Miss Piggy, Fozzie Bear, Animal, and Sam the Eagle on The Muppet Show, and Grover, Cookie Monster and Bert on Sesame Street, among many others. The Muppet character Fozzie Bear is actually not named after Frank Oz, as is widely believed. Fozzie is named after Muppet builder Faz Fazakas, who invented the device which enabled Fozzie to wiggle his ears. In addition to performing a variety of characters, Oz has been one of the primary collaborators responsible for the development of the Muppets over the last 30 years. Oz has performed as a Muppeteer in over 75 movies, video releases, and TV specials, as well as countless other public appearances, episodes of Sesame Street, and other Jim Henson series. His puppetry work spans from 1963 to the present day. He also worked with the puppets on the movie Labyrinth, starring David Bowie. Oz is also well known as the performer of Jedi Master Yoda from George Lucas' Star Wars series. Oz performed the voice and puppet for Yoda in The Empire Strikes Back, Return of the Jedi and The Phantom Menace, and provided the voice of the CGI Yoda in Attack of the Clones and Revenge of the Sith. The conversion to CGI was met with some criticism among fans but Oz himself said that was "exactly what [Lucas] should have done."[6] Oz had a great deal of creative input on the character, and was himself responsible for creating the character's trademark style of reversed grammar. George Lucas was so impressed by Oz's performance as Yoda in The Empire Strikes Back that he spent thousands of dollars on an advertising campaign to try to get him an Oscar nomination for Best Supporting Actor. As an actor, Oz appeared in 1980 as a corrections officer in The Blues Brothers movie, directed by John Landis. He also appeared in later Landis movies An American Werewolf in London, Spies Like Us, Trading Places and Innocent Blood. In 1998, Oz portrayed a warden in Blues Brothers 2000. And while it wasn't for Landis, in 2001 he had a minor part in the Pixar film Monsters, Inc. as Randall's scare assistant Fungus." Source and further information: http://en.wikipedia.org/wiki/Frank_Oz Yoda, Grover, and Frank Oz http://www.youtube.com/watch?v=c9RfjEsEUnU