Chester

Chester is a gooey monster disguised as a purple Treasure Chest that appears in Super Mario RPG: Legend of the Seven Stars. His name is a pun on "chest", and the actual name, "Chester". When the chest is closed, Chester looks exactly like any regular Treasure Box; inside the chest is his body, which resembles a tan Ameboid. Unlike the other chest enemies from Super Mario RPG: Legend of the Seven Stars, Chester is not fought by hitting a Treasure Chest, rather, he's one of the various monster spawned by Magikoopa, and can be found in behind one of the six doors in Bowser's Keep.

In battle, Chester proves to be a tough opponent: indeed, he is one of the strongest enemies in Bowser's Keep, as he has both a high attack and a high defense. Moreover, he is immune against status ailments. Surprisingly, although he is met much later in the game, Chester has less HP than his lookalikes Hidon and Box Boy (encountered earlier in the game), although Chester makes up for that by resorting to the healing move Mega Recover when his HP is low. Chester can also use the spells Flame Wall and Sand Storm, which damage all the party members, or simply attack his opponents by stretching his gooey body in order to hit them. Chester can also summon a Bahamutt to aid him in battle.

Trivia

 * It seems that one Chester is first seen in Monstermama's house in Monstro Town.