The Crimson Prankster is an Emblem Heartless that is found in Kingdom Hearts 358/2 Days. It is one of the bosses at Wonderland. The Crimson Prankster is able to split itself into two identical bodies, as well as to merge and re-split in order to revive a fallen body.
A Crimson Prankster is a bizarre Heartless with spindly legs resembling scissor jacks, arms that appear and sound like they're made of paper, and a head that is made of several segments balanced of top of each other. Each of these segments sports its own face—though all of the faces have the same glowing yellow eyes and jagged mouths—and they alternate in color from pink to indigo. Its arms are black and it often juggles clubs with zig-zagging, black and yellow stripes on them. It wears pink armor with large, indigo shoulder pads, a black codpiece, and has a very thin and small indigo body. The upper halves of its legs are indigo, while their lower halves are pink. Its feet are black, flat, and curl at the tips. Its design is slightly similar to the Kingdom Hearts Final Mix version of the Trickmaster. Despite appearing to be one of the largest Heartless Roxas fights, in reality it is roughly the size of Donald Duck, due to the shrinking potion.
The latter part of the Crimson Prankster's name shows its mischievous and carefree nature. In reference to the Trickmaster, the word "prankster" is a synonym of trickster. This shows the similar nature and appearance between the Trickmaster and the Crimson Prankster. The former part of the Heartless's name could be referencing its Japanese name, "Bleed Performer"; deep crimson being the color of blood.
 Kingdom Hearts 358/2 Days
Roxas is assigned a Mission to Wonderland in order to exterminate a mysterious Heartless. Upon arrival, he drinks the medicine on the table of the Bizarre Room and shrinks as a result. The Crimson Prankster then appears out of the shadows. It has power over fire and the ability to multiply itself, finally falling after both it and its replica are destroyed. The heart it held captive is released, and Roxas's mission is complete.
Attack one copy first. Valor Gear+ is good for this battle. Make sure both of them have near even HP at all times. When one of them is nearly dead, kill the other and destroy the remaining. It does not matter whether you attack the Heartless or its copy first, as they both must be defeated. Use caution when attacking at close range, as the Crimson Prankster may attempt to swat you away.
When the Crimson Prankster leaps into the air, get out of its way as fast as possible. Otherwise, you will suffer damage from the shock wave and wall of fire it emits as a result of its jump. It may also create a pillar of flame directly in front of it. Be careful when it attacks you with a stream of fire. Hide in the hole under the chimney when using Cure or any recovery magic/item. This attack can be predicted, thus easily avoided, when the matches either one of the Heartless carries ignites. You should also be cautious when the Heartless starts to spin while covered in flames.
After the first Crimson Prankster falls, as the other will quickly revive it in a cloud of purple mist. The process of this battle then repeats itself from square one. While defeating the two may seem a bit overwhelming, this fight should be easy if you make use of healing items and your Limit Break. A good strategy to defeating this boss is by lowering both their health bars down to the last bit of the last bar without killing them, then kill one and quickly kill the other before it can revive its fallen comrade.
Also notable is that if you damage one before defeating the other, and the defeated one is revived, it will have HP identical to the other one when it rises, so it does help to lower both of their HP to minimum.