Halicarnassus (Final Fantasy V)

Halicarnassus is a boss and one of the Demons of the Rift in Final Fantasy V. He is the self-proclaimed "master of illusions" and king of Dimension Castle. He poses as a helpless damsel captured by Catastrophe. After the heroes defeat the monster, Halicarnassus gives Bartz the kiss of death and scurries off. Later, he approaches the heroes once more and reveals his true form.

Strategy
Halicarnassus will immediately begin the battle by laughing and turning the party into frogs. Having as many ribbons on your party as possible is the best way to go about defeating him. When he starts "powering up", he will hit for massive damage and probably knock out one party member. Otherwise, his normal hits aren't nearly as devastating.

He also has some powerful spells under his belt, such as Holy. The longer the battle is, the harder it becomes, as he tends to dwindle down the party's HP pretty quickly. The best strategy is to strike him with your party's most effective blows and take him out as fast as possible.