Three-headed dragon (Mitsuzu-Ryu) was an ancient dinosaur Kaiju that appeared in episodes 32 and 33 of the Spectreman show; "The Three-Headed Dragon Rises Again" and "S.O.S.-- The Undersea Oil Field"

_Appearance and Abilities_
The Three Headed Dragon was an ancient three million animal that survive the extinction of its species and other ancient fauna by hibernating underground and adapted to consume oil in that time and was reawaken under the control of Gori, been one of the few Monsters not created by him. The Creature resemble a crocodile type lizard, standing two legs with thin fore legs which he never use; its most discerning feature were the three Saurian heads, with row of blue spikes on top of each of them; each mouth had two long fangs; Two wings hang from its backs and sport a long tail with suction probe on its tip.

The Monster could burrow its way underground at considerable speed – when doing so, it spikes would be visible on the surface glowing in blue light; it spew poisonous smoke from the mouths as well expelled rocks from them as projectiles; the suckle on the tip of its tail could suck oil, which was its power source, as well spew water from it; the tail would be use as an extra extremity to hold a grasp on a opponent; and finally was able of flight.

The Beast's cry seems to be a sped up version of Gyaos, as well had a deep groan as well.

_History_
What starts as a school activity with memorial floating lamps at a lake, it is interrupted by a freak weather, thanks to Gori, who awakens the Three Headed Dragon, now under his control, the beast burrows its way through the ground towards an Oil Refinery; Margaret and Arthur stumble upon the entire class, whose bus was destroy by the Dragon and take them back to the city on their station wagon; As for the monster it breaks through the ground and destroys the installation, consuming the Oil in it while blasting poisonous smoke.

While Gori gives a crash course to Karas about the monster, George arrives to witness as the JSDF Jets retaliate against the creature and it goes as about as one would expect, proving to have no effect on the Three Headed Dragon and some end up crashing as they come in contact with the Poison Smoke, killing some of the pilots. Elsewhere, in one of the Oil Refineries, the Manager (Mr. Morel) comes to learn of the emergency and while he tries to provide an air confidence towards his workers, he himself worries for his wife and daughter as he learns the Monster attacks the city, firing its Rocks and Poison smoke from its mouth; in the Chaos, his wife (Martha) is killed while her daughter (Amy) is rescue by George, who takes an oil tanker truck to escape, but he comes to realize the beast is following them; acting on a hunch, George jumps out of the Truck with the kid and see the beast follow the vehicle until it crashes, where it consumes the Oil.

George puts the kid in a safe place as he runs to make contact with Overlord to Transform into Spectreman and battles the Three Headed Dragon; the titans battle in the Residential Area, toppling some the apartments; Spectreman smacks the daylights out of it with its Spectre Cutters as the Beast tosses him in the fight, smacking him with its tail firing its Rock Spit. In the battle, the giants get wounded; Spectreman a damage arm, while The Dragon walks away with one wing missing, thus remaining grounded. The hero reverts back to George and reunites with the little girl.

The Three Headed Dragon then continues its march towards its next meal, the Oil Fields, following the trail of the Pipelines – Margaret, Arthur and the General come to realize the Nature of the beast and so the Defense force comes to set a trap to eliminate it in a field. Once prepare, the Beast walks in and it falls into a hole cause by the explosive set by the Defense Force, with an entire Artillery Battalion firing at it, but these have no effect on it and are in turn decimated by the Monster's Rock Spit and Smoke. Fortunately, Spectreman arrives to battle the Monster once more.

The Giants battle in the Hole, smacking each other off when they sink deeper into an underground cavern; their underground battle causes the earth to shake, having some soldiers falling into it. Arthur gets hurt and falls unconscious; when he wakes up, he is in the station wagon with Margaret and George, who had reunited with them.

Later, some of them thinking that the Monster is dead, head out to celebrate in a festival, when the Beast re-emerges; in the panic, Amy goes to pick up her doll, getting herself and Margaret corner in the building, but are save when Spectreman shows up and battles the Monsters. Spectreman then grabs it and flies away with it, but drops it onto the sea after the Dragon smacks him on his still damage arm, unfortunately, close to the Oil Refinery where Amy's father works, much to Gori's delight.

As the Monster heads to the Refinery, shutting down Spectreman in the process, the Army request Mr. Morel to assist by burning the oil, to rob the monster of its Energy Source, which the man opposes to do. Morel let's the workers go as he comes up with his own means to stop the monster, as Spectreman re-emerges from the sea to prevent the monster from feeding from the oil – by blowing up the Refinery.

In all my years of watching Tokusatsu,the Morel Family (dunno their name in the original Japanese dubbed) are perhaps the most superfluous Characters ever to be written into one of these; you could remove altogether and it would have zero effect on it. In fact, they just damage it by been there, all because we need the obligatory kid/family subplot, that is far more niche than you see in these.
As the beast retreats to the sea, running away from the fire, John and Otto (WHO UNTIL KNOW WERE NO SHOW) arrive and try to assist by putting it out, later stumbling upon on unconcious Mr. Morel, and help carry him away to safety. The Three Headed Dragon then heads to the Oil Rig Platform off shore, but its path is cut by Spectreman and the two (AGAIN) have another smack down, though this time, the Monsters uses its tail, by smacking the Cyborg and blast a stream of Water.

In his attempt to stop the Monster, Spectreman rips one of the Three heads; despite this, the monster continues towards the Oil Rig, but its attack by JSDF Jets, giving Spectreman a much needed hand, wounding him and rip the last remaining wing off (Yeah, I know! For once, the JSDF was useful here, I'm shock!!). The Monster takes cover underwater, but Spectreman goes under and servers another head. It tosses Spectreman up in the air, but the Cyborg is not deter and dive onto the Dragon once more cutting its tail; this kills the Monster, and Spectreman dismembers what's left of the Kaiju underwater, much to the Frustration of Dr. Gori.

After the battle, the Class continues their Memorial Float ceremony and Amy is reunited with her father.

P.S.: For as far as I can tell, I dunno if Mr. Morel and Amy come to Mourn Martha – she just existed. The two Episode story line feels like poorly, if not rushly, edited (specially the 2nd Episode), but I dunno if this as consequence of the English Editing or whether it was the same in the original.