Requiem

"Requiem" is the 25th episode of season 4 and the 103rd of the overall. It aired on February 19th 2017.

Official Description
Splinter must lead the turtles and the Mighty Mutanimals on the hunt to defeat his old enemy.

Characters

 * Leonardo
 * Donatello
 * Raphael
 * Michelangelo
 * April
 * Casey
 * Splinter
 * Karai
 * Shinigami
 * Letherhead
 * Slash
 * Dr Rockwell
 * Mondo Gecko
 * Super Shredder
 * Rahzar
 * Fishface
 * Rocksteady
 * Bebop

Trivia

 * This Episode first aired in South Korea on December 31st.
 * Splinter dies in this episode.
 * Last appearance of Splinter, alive anyway.
 * This is the first time Leo, Donnie and Raph cry.
 * This is the first time CPR is performed in this show.
 * Lil' Rineo/Evil Ninja Commander's transformation is nearly identical to a giant version of Carter's mutation.
 * Casey's crushing of Shredder in the garbage truck after a fall from a rooftop parallels the same action taken at the end of Teenage Mutant Ninja Turtles (1990 film) - complete with saying "oops", although he is far less jovial when doing so here, due to the circumstances.