Elmo is a character on Sesame Street. Elmo talks in the third person and has a high-pitched voice.
Grover, his best friend, is cuter.
Elmo is not as annoying as Zoe but he's more common. Especially now that they have Elmo's World.

Muppeteer: Kevin Clash

Liz Lot: Before Zoe existed (the good ol' days) Grover was Elmo's best friend. :-P

In Germany, Elmo is called Elma and is female.