His (her?) name is the Evangelist, and he (she?) is pretty weird. A few weeks ago, Gorillaz creators Damon Albarn and Jamie Hewlett invited fans to submit sketches for a new member of the band called the Evangelist, promising that the winning sketch would be redrawn by Hewlett and added to the band. The finalists included everything from a giant squid to a skeleton nun in a gas mask, but now the winning design has been chosen and I'm not quite sure how to describe it… I want to say "Cthulhu hipster." Let's go with that:
Creepy! The Evangelist is meant to be the "light" flip-side to the "dark" Boogieman (who already exists in the Gorillaz universe). I'm not sure I'd trust the above entity upon meeting it, though, I must say. No word yet on what role the new character will play in the band, but it probably won't matter because that conceit has pretty much disappeared anyway.