Megahorn is one of the Ten Terrors, and, as one of the least willing to obey the rules and the most short-tempered, also the first of the Terrors to break the "Rules of Darkness".
He also looks very similar to a Drake creature. He has an extendable neck and wings and bonelike armor equipped with what appear to be dragon skulls. While flying, he can fly as fast of the Mystic Dragon. He also wields a jagged sword which looks much like a dragon's tail. Megahorn, even compared to other Terrors, is also very strong. By slashing his sword, he is able to create shockwaves or summon green fireballs (his fireballs can defeat the Maniticore Megazord in one blast). He also can summon strange black and purple spheres of dark energy. One of his most powerful attacks is the "Lizard Laser", where he blows a powerful blast of green fire from his mouth, and can also breathe powerful blasts of fire or fireballs. During this attack, he fires green lasers from his eyes strong enough to defeat the Solar Streak Megazord. Also, his armor is incredibly durable, able to withstand Daggeron's Ancient Mystic Mode's power, the Manticore Megazord's Striker Spin attack, and even when the Rangers were in Legend Mode and combined their powers with Snow Prince they couldn't hurt him. His armor isn't completely impenetrable, however, an area on the back of his neck was less durable than the rest of his body so it proved to be a weak spot that would lead to his downfall.
Megahorn, along with Serpentina, felt annoyed that the Terrors should follow the Rules of Darkness according to the Stone of Judgment. Believing that the Terrors should destroy their enemies at all costs, he is often frustrated by the Stone not picking him yet. He broke the Rules of Darkness once already in The Hunter. Secretly going up to the surface without being chosen, he fought against Daggeron, who had been busy training with Jenji. He nearly succeeded in destroying Daggeron before Itassis intervened and forced him to leave. Still, Megahorn vowed that he will face the Solaris Knight again.
At the end of Hard Heads, Serpentina claimed that Megahorn would avenge her defeat. In The Snow Prince, Megahorn was at last selected by the Stone of Judgment to attack the Surface World. He happily went, even showing the arrogance to rub it in Gekkor's face. The Rangers had little success against him when they fought him at first but Nick managed to reveal a weak spot on the back of his neck when he repeatedly attacked him. Megahorn, however, was able to revert the Rangers from Titan form and Ranger form altogether and prepared to finish them off when the Snow Prince appeared and battled him. Surprisingly, even outside of his dimension the Snow Prince managed hold his own with Megahorn, though the dragon eventually overpowered him. The Snow Prince then transported Megahorn into his dimension and he, along with the Rangers, battled him amongst the snowy plains. Daggeron, however, was excluded because the Snow Prince did not feel he had learned what he needed to know. Megahorn, however, still could not be defeated, easily and defeated the Rangers once again, along with the Snow Prince, and broke free from the Snow Prince's dimension . This was when Daggeron arrived and battled Megahorn himself, repeatedly attacking Megahorn in both his Ranger form (Solaris Knight) and his Ancient Mystic Mode in the same fashion as Nick did. He managed to rediscover Megahorn's weak point, on the back of his neck, and targeted that area and temporarily defeated Megahorn. This did not stop the dragon-like Terror, however, and he grew to giant size to battle the Rangers once more. It was at this time Sculpin sent Black Lance to assist him since he believed two Terrors would be far more successful than one (and it was secretly to draw Leanbow out) much to Megahorn's dismay, thinking he could handle the Rangers on his own. Black Lance was sent back to the Underworld by Leanbow and Daggeron continued fighting Megahorn in the Solar Streak Megazord. Then by holding Megahorn in place, the Manticore Megazord had the perfect opportunity to strike the back of Megahorn's neck, weakening him enough for Daggeron to finally finish him off by using the Furnace Blast to suck Megahorn in the Megazord's engine and destroy him. Although Megahorn never got along very well with the other Terrors, they weren't shocked that the Mystic Rangers were able to defeat him because the terrors said that he deserve the defeat.