Midoron was the 2nd Gori Kaiju to appear in the 3rd Episode of the Spectreman TV series, Threat of Midoron/Terror of the Blue Scum.

The 2nd of Dr. Gori's creations, Midoron was a lizard transformed into a long neck Kaiju and given to his loyal assistant, Rah/Karax, to sow chaos across the countryside while spreading a Blue Scum disease on the surrounding environment and its inhabitants, which brought the attention of the Pollution Squad to investigate; the Kaiju was capable of having its size shift from a small dog for easy transport to the traditional giant monster. During this period, Dr. Gori was busy working in the construction of his secret base on Earth, with the help of Zeron.

Midoron was the 2nd time where Spectreman, despite the fact it was capable to size shift, still decided to fight the beast in its Human size and took it down with SpectreFlash, stunning the Beast, making it lose its balance and falling down a cliff to its death; its body disintegrating into bones.

Midoron was Dark Green in color, with three horns on its head and one on its snout, with a mouth full of teeth; it walked on four legs and a sport a long powerful tail, giving it a traditional look of a European Medieval Dragon. It spew a green Toxic mist from its mouth. Midoron was the 2nd Monster in the series to be portrayed by a miniatures and a hand puppet for the head shots scenes, with stop motion been used when walking, a rarity in Tokusatsu due to the time consuming nature of the art forms under the time constrains this shows tent to work on, though these were brief scenes. It used a modified Barugon cry for its roar.

Midoron was actually made for the unair pilot of Jaguarman and was originally named Great Magumon, before the monster was re-used for Spectreman under the new name.