Gold Goomba

The Gold Goomba is a Goomba that is made out of gold.

Super Mario RPG: Legend of the Seven Stars
Gold Goombas appeared in the Goomba Thumping minigame found in the Pipe Vault

Mario Party series

 * They appeared in the Mini-game Trap Ease Artist and hitting them gets you three points in Mario Party 6.
 * They appeared in the Mini-game Royal Rumpus in Mario Party 7.
 * They appeared in the Mini-game Goomba Wrangler in Mario Party DS.
 * Lastly they are in the Mini-game Ka Goomba! in Mario Party: Island Tour.

New Super Mario Bros. 2
Mario or Luigi touch a Gold Ring it will turn all regular Goomba's into Gold Goomba's. You get 5 Coins if you kill it.