Paper Mario: Sticker Star Easter eggs

Hidden Health Heart at Yoshi Sphinx
While at the Yoshi Sphinx map progress through the level until you reach the comet piece at the top of the sphinx. Next head to the top of the screen while on the sphinx, you will fall to a platform below with a Health Heart on it. Collect the heart to increase your max health by five.

Note: It is very important to stay on the purple mat while walking off the sphinx. Also to get an idea of where the heart is walk all around to the far side of the sphinx after you start the level. You will see the heart floating on the platform out of reach.