The Kappa is a type of water sprite living in the pond by the fisherman's tent. If you throw a fish into the pond between the hours of 9am-5pm he will come up and give you a Power Berry.
- If you throw in a large fish, he will give you a Power Berry.
- If you throw in a small/medium fish he will give you a Blue Power Berry.
It is important to note that the Blue Power Berry does nothing. It is supposed to half your fatigue gain rate (rounding down), which is an incredibly useful ability. However, due to a game developer flaw, the normal Power Berry will both increase your stamina and bestow this ability upon you.