More Walter-ness

Drew this yesterday evening during a train ride home.
While drawing, I overheard an amusing discussion of some fellow passengers near me (even with headphones on, listening to music), whether this is a female or male. It ended with the statement of the lady sitting next to me, that "it has to be a male, since he has a mustache... or not?".

...Does my Walter really look that female? ._.;

Ah well.
More train ride skteches can be found on my sketchblog [link] .