Has the coloring changed since the last post? The hammer's handle doesn't look like a "wodden" color to me.
Sure the hammer isn't transparent (not all glass is - some is frosted) but the color seems about as right as you can get it in a comic strip.
ManishJain, Loblong, Scot is trying to point out that Wally is almost as useless as a glass hammer (hammer made of glass) and a bag of nothing. Think of it, what use can be a hammer made of glass? A hammer for pounding glass is still useful.
I will also say that Dilbert guys (Scot Adams et al) should allow viewing at least 20 comments on one page. It is a little irritating having to click just to see last five comments.
I guess the hammer is actually made of glass, since Wally is in a classroom with useless classmates and a hammer made of glass would be very very useless, don't you people think? :-)