Babasu are enemies that appear in The Legend of Zelda: A Link to the Past.
A Link to the PastIce Palace, the fifth dungeon of the Dark World. They live in the walls and will occasionally come out and slither across the room. Sometimes they'll have two holes that are parallel with each other on the opposites sides of a room, and they travel between them. When Link sees a sparkle in a hole in a wall, he must prepare his sword since that's a sign that a Babasu is about to run out.
If a Babasu comes into contact with Link, it will do two full hearts of damage. Babasu are rather weak and Link can defeat them with a simple sword slash from his Master Sword. However, what makes these creatures difficult is they are sometimes found in rooms with moving platforms as well as Blade Traps, making it very easy to take damage while trying to defeat them.