An Emerald Serenade has a smooth, conical, body covered in vertical stripes that alternate from green to white. Its Heartless emblem is emblazoned on its chest. The top of its body flares outward and forms a jagged "collar" below the Heartless's spherical, pitch black head. It also wears a conical, black hat that is green on the inside and has a jagged brim and a thin, curled tip. Like many Heartless, the Emerald Serenade has glowing yellow eyes. Its seemingly useless feet sport three small, thin toes. The Emerald Serenade is one of the largest Heartless in its family, only contested by the Crimson Jazz.
Like many other Heartless in its family, the Emerald Serenade's name refers to a color—in this case, emerald green, the same as the Emerald Blues—and a musical term—in this case, a serenade, a piece of music appropriate to the evening, characteristically played outside the house of a woman, to woo her.
The Emerald Serenade is, to say the least, a great annoyance. They do not attack in any way, but they remain in constant motion and move in uneven patterns at relatively high speeds. They also have large amounts of HP.
The best way to defeat an Emerald Serenade is to watch the dot that represents it on the map that appears on the Nintendo DS's bottom screen as it moves along its specific and unchanging path. The player should then attempt to find a location along this path and remain stationary, thus allowing a chance to ambush the Heartless with a Blizzard spell whenever it comes into view. There is a strong chance that this spell will freeze the Emerald Serenade, increasing the damage it takes for a short time while keeping it stationary. This is the time to launch any physical attacks or other magic, such as Fire, Aero, or Thunder. It is important, however, that the player cast either Blizzara, or Blizzaga well before the Heartless comes into view, as the slow casting of these spells may allow the Heartless to pass free of damage, meaning the player must wait for it to travel around the area a second time before another ambush attempt can be made. Thus it is important that the player bring several Ethers, due to the strong reliance on magic needed when facing an Emerald Serenade.
It is highly recommended when a player attempts to defeat an Emerald Serenade in Mission Mode that they fight as Xigbar due to his attacks' long range. Lexaeus is also a strong choice when battling an Emerald Serenade in Mission Mode, as his attacks' great strength can be devastating to the Heartless's health after it has been frozen by a Blizzard spell. While the recommended process of defeating an Emerald Serenade may seem endless and aggravating, it will ensure victory whether the Emerald Serenade is faced in Story or Mission Mode.