1337. Bumblebee

Bumblebee (known as Bumble in Japan, Moscardo in Portugal, Űrdongó in Hungary, Maggiolino in Italy) is the "little brother" of the heroic or protagonistic Autobot faction and a mascot, constantly striving to prove himself in the eyes of the other robots - especially his leader, Optimus Prime. This often causes him to take risks that put him in danger. Although a bit of a wise-cracker, he is a capable and reliable messenger and spy, his small size allowing him to go places that his larger commanders cannot. He is highly fuel efficient, has great visual acuity, is particularly adaptable to undersea environments and transforms into a Volkswagen Beetle. He was later reconstructed in a stronger, more mature form as Goldbug.
Bumblebee is established as the smallest of the first year Autobots, but his actual size varies greatly in the various media, ranging from the same size as other Autobot cars to barely taller than a human. His only official height was in an early issue of the Marvel comics where it is stated he is 15 feet tall.
Bumblebee's primary function in the original Transformers animated series and comics was to serve as the "young" character with whom the young viewing audience could identify. To this end, he befriends the Autobots' primary human ally, the young son of the Witwicky family (Buster in the Marvel comic and Spike in the cartoon), a concept that persists into the 2007 live-action film. Although a well-known character because of this, Bumblebee is quite unusual in that, unlike many other Transformers, his name has not been re-used and applied to unrelated characters throughout the ensuing twenty years of Transformers media, due to the loss of the trademark until recently. His role as the "young yellow character", however, has inspired other Transformers characters with the same role such as Cheetor and Hot Shot.