Absolutely Safe Capsule

The Absolutely Safe Capsule is the second part of the boss battle against Porky Minch in Mother 3. Porky made Dr. Andonuts invent it for his protection. When the player damages Porky enough, Porky retreats to his Absolutely Safe Capsule, but because it cannot be damaged, the battle is over. Dr. Andonuts then appears and explains that, although it makes anyone inside invincible, there is no way to leave the capsule.