Grosden was a Salamander like Reptilian Warrior Beast of the Mikene Empire who was introduced in the 1974 MZvTGGoD OVA as one the monsters unleashing its attack on Humankind - Grosden was sent to Moscow where it fought against the Red Army's tank battalion. Grosden weapons were his acid spit and his eye laser beams, his real face was located on the top of the Cyborg's head.

Grosden along with other Warrior Beasts, was tasked to kill Koji and Mazinger to avenge the death of his fellow Warrior Beast in Tokyo and help unleash an onslaught of the Empire's strength on the out number hero but that ended when Great Mazinger arrived and team up with the damaged Mazinger Z to defeat the General Juuma's revenge squad. Grosden was the last Warrior Beast to be destroy before Mazingers killed Juuma - as it was firing his laser beams on Great, Great took the chance to threw his Great Boomerang, slicing the Reptilian Cyborg from head to tail.

His only other appearance in the franchise is in the Mazinger Zero Manga. Grosden had an almost similar design to another Reptilian Warrior Beast Gomodora http://mazinger.wikia.com/wiki/Gomodora