Destroy All Monsters (1968)
At the turn of the century, Earths monsters have been safely rounded up and studied on Monsterland Chaos erupts when a race of she aliens known as the Kilaaks unleashes the monsters across the world
Son of Godzilla (1967)
A reporter stumbles upon weather experiments on a tropical island, discovering giant mantids, a cast away woman, and an infant monster that Godzilla must adopt and learn to raise as one of his own
Matango (1963)
Shipwrecked survivors slowly transform into mushrooms