Pandorite

The Pandorite is an enemy disguised as a Treasure Chest that appears in Super Mario RPG: Legend of the Seven Stars. The creature inside the chest is a squat, pudgy ghosts, similar to the creature inside the Clusters. It is encountered in Kero Sewers.

The Pandorite possess both high physical attack and defense, and equally high magical attack and defense. It is immune to all special attacks, Mario's various Jump attack excepted. In battle, the Pandorite can cast various fire spells, including Flame and Flame Wall. The creature inside the chest also uses the attack Scream, which can induces the Fear status ailment and Carni-Kiss, as well as physical strikes.

Defeating Pandorite rewards Mario's party with ten experience points, thirty Coins, a Flower Jar, and the Trueform Pin. Later in the game, if Mario returns to the Treasure Box that previously held the Pandorite, he will receive an additional fifty Coins. In fact, as soon as Mario leaves Pandorite's room, the Treasure Box will be filled again, meaning Mario can simply exit and reenter the room to claim the additional reward.

Several monsters similar to Pandorite appear in Super Mario RPG, these being Hidon, Box Boy, and Chester.

Trivia

 * Pandorite's name comes from the Greek legend of Pandora. According to the legend, Pandora was the first female human ever created. Pandora opened a jar, now called "Pandora's Box", that released the world's misfortunes, such as plague, crime, poverty, greed, and war.
 * Pandorite (and its relatives) are the Super Mario RPG equivalent to the Final Fantasy series Mimics, which are also monsters that disguise themselves as treasure chests. Both Super Mario RPG and the Final Fantasy series were developed by Square Enix.  In fact, Mimics appeared in the game Mario Hoops 3-on-3.
 * If the player finds a roulette ? chest and gets three different icons, the last "monster chest" encountered will be battled again.