Ah, Neopets. I remember that site. Those were good times, back in the day when it was cool to play Neopets (and Pokémon too for that matter). I still log in every couple months or so to check on my old stuff. The stock market game is actually pretty addicting, along with Neoquest II :)
I use my same username there, too. Although when they asked me for my name, I just grabbed my student directory, opened to a random page, and wrote down the first name that I saw. Funny thing is, I ended up meeting the guy who's name I copied and we became good friends (we even go to the same high school now) but that's another story...
k, I just read your conversation with destinedjagold and I realized that he actually didn't change the blob itself. If it doesn't show up in Unlz nor in an Overworld Editor, then the only thing I can think of would be to try opening it up in Tile Molester or a similar program. Although finding the offset would be the tricky part. As destinedjagold said, I'd ask mitchel1 about how he did it (although I, personally, haven't seen his edited sprite). Good luck with that ;)