Godzilla Vs. Mechagodzilla aka Godzilla Vs. the Bionic Monster aka Godzilla Vs. the Cosmic Monster

For Godzilla's 20th anniversary Toho wanted a new opponent, something he had not faced before. Remembering they had Kong face a robot duplicate, they decided to have Godzilla face his own mechanical doppelgänger. Also made the aliens controlling Mechagodzilla, in honor of King Kong, are apes, or maybe it was because of the popularity of the Planet of the Apes movies.  
      

Son of Godzilla

Godzilla's south seas vacation continues and we are introduced to Minira or Minilla the small grey pudgy daikaiju nobody asked for.

Ebirah, Horror of the Deep aka Godzilla Vs. the Sea Monster

Taking a break from the city destruction and world saving Godzilla takes a south seas vacation in a film originally written for King Kong. We also have a new director Jun Fukuda, Sadamasa Arikawa taking a more active role in effects, and Masaru Sato does the score.