Reminds me of
Kid Radd. It was before the days of flash, and it was done using browser hacks and animated gifs. (before the days of css, as well.) It was also very small: the gifs were, at most 64x64 pixels (rare 'special' annimations may have been up to 256).
Unfortunately, the bowser hacks have dated, and it no longer works in IE6+, and even firefox has some issues.
The writer was a better hacker than he was an author, but the story does work. (even if the animations don't.)