Metallo was built before the destruction of Krypton. Superboy discovered the existence of Metallo, while stranded on an asteroid because of a kryptonite dust cloud. The robot was destroyed, but it is unknown how it was destroyed.
Metallo was built before the destruction of Krypton. Superboy discovered the existence of Metallo, while stranded on an asteroid because of a kryptonite dust cloud. The robot was destroyed, but it is unknown how it was destroyed.