Kero Kero Keroppi no Bokutachi no Takaramono  

けろけろけろっぴのぼくたちのたからもの, Keroppi in Our Treasure, Hello Kitty and Friends: Our Treasure, Keroppi and Friends: Our Treasure, Kero Kero Keroppi no Boku-tachi no Takaramono

Keroppi finds a sparkling stone which ends up bringing out the greed within himself and his friends.