For a huge, nasty, and angry monster, Godzilla has managed to acquire an impressive list of allies and friends. Some of Godzilla’s friends were either enemies earlier in the series or they became enemies in later movies. When Godzilla makes an alliance, there is usually a reason for it. It is safe to say that the king of the monsters only hangs out with those that he chooses to, and not those that he feels he has to.
5) Rodan
Rodan and Godzilla have a very strange relationship in all of the movies they appear in together. They were both in the 1964 movie “Ghidorah, the Three-Headed Monster” where they open the movie trying desperately to kill each other. A few flowery words from Mothra and the two enemies start working together.
In the 1965 movie “Godzilla Versus Monster Zero”, Godzilla and Rodan seem to instinctively team up to chase King Ghidorah first away from Planet X, and then away from Earth.
In the 1993 movie “Godzilla Versus Mechgodzilla 2” Rodan twice sacrifices his life to save Godzilla after Godzilla had tried to kill Rodan earlier in the movie. This strange dynamic is never explained.
4) Anguirus
Anguirus first appears I the 1955 movie “Godzilla Raids Again” as an enemy of Godzilla. It is never explained why, but the next time we seen Anguirus in the 1972 movie “Godzilla Versus Gigan” the two are friends. Anguirus is portrayed as such a close friend to Godzilla in the 1974 release “Godzilla Versus Mechagodzilla” that Anguirus does battle with Mechagodzilla because he recognizes that the robot is not the real Godzilla when it is not apparent to anyone else.
Anguirus appears in “Godzilla: Final Wars”, but his appearance is quick and Godzilla dispatches him in less than 5 minutes. In the video game “Godzilla: Unleashed” Anguirus is given the ability to bowl people over by curling up like an armadillo and rolling over them. This power is on display in “Godzilla: Final Wars.”
3) Jet Jaguar
Jet Jaguar was created as the result of a contest that Toho held that allowed kids to design their own super robot. Toho wanted to have an answer to the popular Ultra Man character that was ruling the Japanese television airwaves in the 1970’s.
Jet Jaguar looks a lot like Ultra Man, but he does not possess any of the powers that Ultra Man has. All Jet Jaguar can do is fly. Toho was going to feature Jet Jaguar in his own movie fighting the monster Megalon, but the studio decided that an unknown robot would not carry the movie by himself. To sell tickets, Toho put Godzilla in the movie and the result was the 1973 release “Godzilla Versus Megalon.”
Godzilla wound up saving the day a little too much in the movie, and Jet Jaguar was never seen as a viable character for any future Godzilla movies.
2) King Seesar
King Caesar started out as an ancient god to the royal family of the island of Okinawa in the 1974 movie “Godzilla Versus Mechagodzilla.” He teams up with Godzilla to defeat Mechagodzilla. King Caesar was able to move quickly and he could capture and return an opponent’s laser beams with his eyes.
In “Godzilla: Final Wars” King Caesar is seen destroying Okinawa before he is kidnapped by aliens to fight, and lose to, Godzilla.
1) Godzilla Junior
The character of Godzilla Junior, known in the earlier movies as Minilla, first appears in the 1967 movie “Son of Godzilla.” Minilla would appear again in the hastily, and poorly, produced 1969 movie “Godzilla’s Revenge” and then he disappeared.
Godzilla Junior reappears in the 1993 movie “Godzilla Versus Mechagodzilla 2” and we get to follow his development until his defeat by Destoroyah in the 1995 movie “Godzilla Godilla Versus Destoroyah.”
Junior saved Godzilla’s life in one of the only times that humans were able to kill Godzilla. In “Godzilla Versus Mechagodzilla 2” it is Junior that asks Rodan to sacrifice himself to save Godzilla after the humans had brought Godzilla down by destroying the brain in the base of his tail.
The senior Godzilla returned the favor after he defeated Destoroyah, and then breathed his life force into Godzilla Junior, allowing Junior to carry on as the new Godzilla.
“Godzilla”, IMDB.com