From Zelda Legends Wiki
The Mad Batter is a Bat-like creature who lives under the ground of Koholint Island. If you sprinkle some Magic Powder on his living space (which resembles a well,) a small creature will float out and materialize into the Mad Batter. The Mad Batter will then complain about how you woke him up from a fine nap. As retribution, he makes you carry more bombs, arrows, or Magic Powder. You can wake him up three times: Once in the Mysterious Woods, once in Tal Tal Hieghts, and once in the sea.