Trickmaster

The Trickmaster is a boss from Kingdom Hearts and Kingdom Hearts: Chain of Memories. For defeating him, you get the Wonderland specific accessory the Ifrit's Horn

Kingdom Hearts
Heartless appeared in wonderland to kill Sora and company.

Kingdom Hearts: Chain of Memories
"The Heartless in Wonderland who stole the Queen of Hearts's memory. Victims of memory theft do not even remember what he is they forgot."

Kingdom Hearts
The Trickmaster is a special Heartless with the ability to steal people's memories. He was sent to find the Wonderland keyhole and destroy Wonderland's heart. He was also sent to capture Alice. Though he succeeded in the latter, Trickmaster was defeated before he could destroy Wonderland. Throughout most of the adventure in Wonderland, Trickmaster is referred to as the shadows or as the darkness (especially by the Cheshire Cat). He was the one who attempted to steal the heart of the Queen of Hearts.

Kingdom Hearts: Chain of Memories
Trickmaster briefly appears as a boss and a thief, stealing the Queen's memory.

Kingdom Hearts: Final Mix
In Kingdom Hearts: Final Mix, Trickmaster was recolored with pink replacing red and light purple in place of black, giving him a more Wonderland-ish look.

Card
see:Trickmaster (Enemy Card)

Trivia

 * Despite appearing to be one of the largest Heartless Sora fought, in reality he was roughly the size of Donald Duck; Sora battled him while they were small.
 * The color pattern of this enemy may have inspired the design of the Wheel Master, a boss part of the Unbirths