Panther Girl of the Kongo (1955)

Jean Evans of an international wildlife foundation, who is known to Africa as 'the Panther Girl' because of her bravery in jungle living, stumbles on a plot by a mad scientist to frighten the natives out of a diamond-laden district by chemically growing crayfish to giant size, and enlists the aid of a game hunter friend to prevent a monster rampage and bring the culprits to justice.