Bwa ha ha! I'm no ordinary Goomba... I am Goomboss, the Great Goomba, the Grand Poo-Bah Goomba.
~ The Goomba King, Super Mario 64 DS
The Goomba King (real name: Goomboss), is the mighty king of the Goombas. He despises Mario because of his blue (he hates this color) boiler suit and is an ally of Bowser. He first appears in Paper Mario, where he serves as the opening antagonist.
Sometime before Paper Mario, the Goomba King was made king of the Goombas by Bowser with the Star Rod, because he begged him. He lived in a castle on Goomba Road with his two minions, the Red and Blue Goomba.
After Mario and Goombario defeated the Red and Blue Goombas, they come to the Goomba King's castle and all three of them challenge Mario. The Goomba King only has 10 HP. After he is defeated, he runs back in his castle and Mario has to push a button that makes his castle unfold and launches him in the air to a mountain in the background.
In the ending credits to Paper Mario, he is seen stuck upside down in a tree.
Super Mario 64 DS
He appears again as a boss in Super Mario 64 DS, where Yoshi must defeat him to free Mario. To defeat the Goomba King, Yoshi must eat the Goombas that the Goomba King spawns behind him and spit them back at him. After three hits, the Goomba King explodes into a swarm of Goombas.
Mario Kart DS
The Goomba King appears in Mario Kart DS as a rival in the missions section. Toad must complete three laps around Baby Park before the Goomba King does. While in front of Toad, he may turn around to kick a Goomba at Toad (sometimes a mushroom instead). After each lap, the Goomba King grows in size and becomes faster. In addition, Toad must prevent all his balloons getting popped during the race.
Paper Mario- Boss Battle- Goomboss
Super Mario 64 DS - Episode 4 - Stompin' Goomboss!
Mario Kart DS- Goomboss
Goomba King is last seen (outside of the credits) flying into the distance from a great height, and it is unclear whether he survived. This also happens with Queen Chrysalis in My Little Pony: Friendship is Magic, although she does return in the comics.