Mighty Fish Food (おいしい？ 万能魚, Oishii? Bannougyo, lit. Delicious? Almighty Fish) is an event in Tomba!.
Feed the fishes in the Ol' Pond with some fish food and collect the Mighty Fish.
Go to the Ol' Pond and stand next to the water before using the Mighty Fish Food from the Item Screen. Then jump into the water and collect the Mighty Fish, which is now swimming around the pond, to clear the event and instantly reach level 10 in red experience. This can also be done in the pool with the pink pipe in the Haunted Mansion to maximize green experience and the Masakari River to maximize blue experience.