The Underwhere fountain

The Underwhere fountain is a special fountain that spews out orange water found in The Underwhere, in the game Super Paper Mario. As the name suggests, it restores all of Mario and Co.'s HP at no cost if they step inside of it, making it very similar to an inn. It is located right after the beginning area of The Underwhere, next to a few Shaydes.

If Mario and Co. needs more than 99 HP restored, instead of a number inside of the heart that signifies HP restoration, it is simply blank, while nothing happens at all if their HP is full.