Episode 44

Happy Birthday Time is the twenty-second episode of Season 2 and the forty-third episode of the Assassination Classroom anime. It premiered in Japan on June 9, 2016.

Summary
After taking out the army unit stationed inside the mountain, Class 3-E reunite with Korosensei. Their celebrations, including a happy birthday to mark another anniversary of Korosensei and Ms Yukimura meeting for the first time, are brutally cut short by the arrival of Yanagisawa and the second God of Death, now a tentacled monster. The pair then battle Korosensei with the students unable to help.

Anime and Manga differences

 * Craig Houjou and the Wolfpack was officially not appeared in anime as this is the last episode that featuring Houjou and Wolfpack on manga itself.
 * Craig Houjou was replaced by an Elite SDF (Self-Defense Force) Commander while the Wolfpack was replaced by Elite SDF Soldiers.
 * The light on Lance of the Heavens on anime was less bright for the width compared to manga.
 * When Megu uses her trap, the soldiers are strangled on the neck and finished by Hinata and Kimura while on anime she make the soldiers upside down with her trap.