Gorillaz secret guest stars

Reader Maclaine Diemer alaerted us to this new Gorillaz video which, in addition to being just excellent, features a couple of guest stars. One is obvious — the star of many comic-bookical movies. The other — appearing at around the 4:00 mark — could be an homage to another well known character? Since this is the first part of an evolving story, perhaps this mysterious figure will be back in future installments.