I always thought they were a type of Chozo just wilder or a type of defense cyborg which are part Chozo and part machine that the Chozo built to protect their weapons.

The gold one in Super Metroid was also called an Torizo.



Some of the Chozo statues on Metroid Zero Mission have pointier beaks than the Torizo and the Chozo statues on Super Metroid and the ones on Metroid Fusion.

The one on Fusion even had a different name.

This just makes me think that there were different species of the Chozo.