You can also use photshop magic wand to select the background, then use Select>modify>expand to expand your selection into those stray pixels.
I threw up a few monster icons I had laying around, just in case anyone has a use for them. You can see a picture here:
http://www.techno-mage.com/~targa/monsters.jpg
And/or download the file as a photoshop .psd file here:
http://www.techno-mage.com/~targa/monsters.psd
Saber: See if your program is using an "anti-alias" setting on the fill command. That's usually what causes you to have off-color borders. Turn off antialiasing and it should fill black right up to the edges of your sprites. Alternatively, in photoshop you'd be working with layers, and could merge the layer with the sprite down onto a solid black layer.
[ February 02, 2004, 17:28: Message edited by: Targa ]