From the Super Mario Wiki
Bowser's handprint on a golden frame.
“It's Bowser's Handprint! It's one of a kind!”
—Bowser, Mario Party Advance
Bowser Print is a Gaddget in Mario Party Advance. It can be obtained by completing the quest Final Showdown. Bowser Print is awarded after Bowser accepts defeat in Shroom City. As the name implies, it is Bowser's handprint. When used, it displays a red handprint on a golden border frame.