When a powerful foe returns, the Turtles' only hope lies within the most dangerous place they've ever been: Splinter's mind.
| Name | Type | Role | |
|---|---|---|---|
| Josh Riley Brown | Writer | ||
| Vladimir Radev | Producer | ||
| Maurice LaMarche | Guest Star | Foot Brute | |
| Keiko Agena | Guest Star | Hamato Atsuko | |
| Rob Paulsen | Guest Star | Foot Lieutenant | |
| Gwendoline Yeo | Guest Star | Hamato Karai | |
| Zelda Williams | Guest Star | Foot Recruit | |
| Matthew Yang King | Guest Star | Hamato Sho | |
| Kat Graham | Guest Star | April O'Neil | |
| Hoon Lee | Guest Star | Shredder | |
| Roger Craig Smith | Guest Star | Baron Draxum | |
| Eric Bauza | Guest Star | Splinter | |
| Andy Suriano | Executive Producer | ||
| Ant Ward | Executive Producer | ||
| Sebastian Montes | Director |