Frank Everdij wrote that he has managed to extract boot logos from SGI EPROM firmware:
Last couple of weeks I have tried to reveal some secrets of the EPROM-firmware of several SGI's and I succeeded in extracting the Boot Logo for three systems: the Indy, the Indigo and the O2. I have included the gifs to this email (my first in Pine!)
Maybe someone can use this as elements for a custom Wallpaper...
I've rolled the three logos into tarball which you can download here. This is really very cool and I may just throw together some custom wallpaper myself! :)