Journey to the Center of Mikey's Mind

"Journey to the Center of Mikey's Mind" is the 6th episode of season 4 and the 84th of the overall. It aired on January 17th 2016.

Official Description
When microscopic aliens invade Mikey's mind, the Turtles have to chase them through the strange world of Mikey's subconscious.

Characters

 * Leonardo
 * Donatello
 * Raphael
 * Michelangelo
 * April O' Neil
 * Casey Jones
 * Fugitoid
 * Belly Bomb
 * The Neutrinos
 * Lord Dregg

Trivia

 * First and only appearance of Belly Bomb and The Neutrinos.
 * Mikey is the first turtle to be seen as a tot.
 * Leo, Donnie and Raph wore there Spirit Quest gear but was only part of Mikey's imagination
 * Leatherhead, Ice Cream Kitty, Pigeon Pete, Mondo Gecko, Tiger Claw, Sir Malachi, Renet, Chris Bradford, The Punk Frogs, Dave Beaver, Dash Coolstar and Crognard appeared in this episode but as Mikey's imagination.
 * Mikey's memories were from Mazes and Mutants and A Foot Too Big, which Big Foot was also seen in.
 * When the Turtles were in a red curtain room, with Wacky Mikey talking backwards, this is a reference to Twin Peaks.
 * The Fugitoid telling April and Casey to stay on the Ulixes as the cantina would not take kindly to Terrans in the establishment is a call back to Star Wars Episode IV: A New Hope, where Luke tells C-3PO and R2-D2 to wait outside after the Mos Eisley cantina bartender tells him that they don't take kindly to droids in the establishment.
 * When Leo, Donnie and Raph meet Mikey in his subconscious, Mikey's introduction is backmasked. He says "but you can't understand me because I'm speaking backwards. Welcome to Mikey's magnificent mind!"