From the Super Mario Wiki
Mad Goombas are a derived species of Goomba found in Super Princess Peach. They are a normal Goombas infused with energy from the Vibe Scepter, giving the ability to rage wildly. Their outside appearance is the same as a normal Goomba, but reddish with an angry expression. When they stomp their feet, an earthquake follows, stunning Peach if she is nearby. The blue Sad Goombas are the opposite of the Mad Goombas.