Anguirus

Anguirus is an mutated Ankylosaurus and was Godzilla's first official kaiju enemy. Luckily, Anguirus befriended him after, making him a loyal Earth Defender.

Godzilla Raids Again
Anguirus is first seen fighting against Godzilla. The two eventually fell off a cliff and into the ocean. Scientists research Anguirus and find out that Anguirus and Godzilla lived at the same time millions of years ago. Anguirus hated hostile creatures, explaining the rivalry.

Eventually, Godzilla arrives in Osaka and Anguirus follows him. The two fight each other, destroying the city. Godzilla bites Anguirus' throat and burns him, apparently killing him.

Destroy All Monsters
Anguirus was captured and taken to Monster Island, along with all the other monsters. Anguirus became allies with Godzilla, ending their rivalry, and the monsters lived in peace. Unfortunately, an alien race known as the Kilaaks took control of the monsters and sent them on a rampage through Earth. Anguirus was used to guard the alien base. When the humans broke the control the aliens had on the monsters, the aliens unleashed Godzilla's arch-enemy King Ghidorah. But with their combined strength, the monsters killed Ghidorah and lived on Monster Island in peace once again.

Godzilla vs. Gigan
When King Ghidorah and Gigan, under the control of the Nebula M aliens, attacked Japan, Godzilla realized something was wrong and sent Anguirus to Japan. However, when Anguirus got to Japan, the military drove him away, not knowing his intentions. Anguirus told Godzilla and the two swam to Japan to see what was wrong. They saw King Ghidorah and Gigan and challenged them. While Godzilla battled his nemesis Ghidorah, Anguirus battled Gigan. Gigan proved to be a tough opponent, kicking Anguirus repeatedly and slashing Anguirus with his chest saw. This was further complicated by the Nebula M aliens shooting a laser cannon from inside the Godzilla Tower. When the tower was destroyed, Anguirus and Godzilla gained the upper hand and drove off Gigan before giving Ghidorah a brutal beating and sending him flying away as well. Anguirus and Godzilla then swam back to Monster Island.

Godzilla vs. Mechagodzilla
When Mechagodzilla rampages through Japan in a Godzilla costume to fool the people into thinking Godzilla is attacking, Anguirus confronts him. Anguirus had known that this was not the real Godzilla. However, Mechagodzilla proved too strong and quickly overpowered Anguirus, forcing him to retreat.

Godzilla: Final Wars
The alien race the Xiliens took control of Anguirus and the other monsters and unleashed them on Earth. Anguirus attacked Shanghai, China. Anguirus killed thousands, and even though the warship Karyu was sent, it could not stop Anguirus' assault. However, the Xiliens transported Anguirus and the other monsters away, claiming to have saved them. When the humans found out the Xiliens were planning world domination, they released the monsters again. Anguirus was sent to finish off Shanghai.

However, Godzilla was released from his icy prison and caused the Xilien's plan to go downhill. They sent monsters after him, but he defeated them all. When Godzilla reached Mt. Fuji, Anguirus teamed up with Rodan and King Caesar to fight him. Godzilla quickly gained the upper hand and Anguirus was knocked into Rodan and Caesar kicked him at Godzilla, but he landed on Rodan instead. King Caesar was overpowered and defeated soon after and the monsters were stacked on top of each other as Godzilla left them alive but unconscious.

Godzilla: Planet of Monsters
Anguirus appeared in 2005. He and Rodan attacked Beijing. They were then both killed by Hedorah.