The Ultimate Gamer was a character that appeared in the Back to the Sewer episode SuperQuest. Michelangelo describes the Ultimate Gamer as being one of the best and most feared players in the game of SuperQuest. The Ultimate Gamer first appeared as a cloaked ferryman, disguised as an NPC. Later, he appears to attempt to steal the treasure chest that contains Splinter's data bits. The Turtles and Elfinator work together to defeat the Ultimate Gamer, with Leonardo taking on the form of a white lion to land the final blow. It is then revealed (to the viewer, but not the characters) that the Ultimate Gamer is actually controlled by a geeky Asian girl in the real world.
The Ultimate Gamer's armor is similar to and may have been designed to echo the Shredder's.