yes, very old Tutorial^^
You need:

A *.TGA, *.PCX, *.DDS or *.BMP sprite.

If you want to make it transparent, you will need
black parts of your sprite(tga, pcx, bmp).

pcx and bmp don t know transparency, so you will need
the overlay flag.(the black parts will be invisible)

Tga and DDS do have an alphachannel.