|Home world:||Yapool's Dimension|
|First appearance:||Ultraman Ace episode 6 "Pursue The Mystery of The Transformation Choju" (1972)|
Subtitle: Transformation Super-beast (変身超獣 Henshin Chōjū?)
- Height: 63 m
- Weight: 46,000 t
- Origin: Yapool's Dimension
Brocken was created by Yapool in his laboratory by combining the bodies of an Alligator with an unknown space creature, merging them to form a new choju. Yapool then sent Brocken aboard a space vessel that was heading home to Earth, hijacking it in the process and possessing one of the crew members. While in its host's body Brocken appeared to act normal, but once his host's son found an extra mouth on his hand the guise was revealed. The son informed TAC, who were quick to take action. When Brocken was found out, he fled TAC until he reached one of their HQs, where he took his true monstrous form and attacked the city with his flames. TAC quickly responded with their gunfire and jets, but they were no match for Brocken's strength. During the fray, Hokuto was caught in Brocken's right arm jaws. Minami ejected from her jet and together they transformed into Ultraman Ace, severing Brocken's right arm in the process. At first, Brocken had the upper hand in the battle with its brute strength and laser attack. Then an Ultra Sign was sent by the 4 Ultra Brothers which encouraged Ace, who managed to stand, and destroy the choju with three Ultra Guillotines, severing Brocken's head, arm, and whips, killing the choju. With Brocken dead, his host was soon free of the monster's control.
- Brocken's roars are modified elephant trumpets. They would later be used and modifyed for the Toho Monster, Titanosaurus.
- There is a brief continuity error during the battle between Ace and Brocken. When using his claw lasers, Brocken has both from his front arms even though one was destroyed when Ace transformed.
- Although not physically seen, Brocken is one of the monsters that makes up Beryudora's Body in Mega Monster Battle: Ultra Galaxy Legend The Movie.
- Brocken's design and suit are very similar to Dodongo from Ultraman.
Powers and Weapons
- Flames: Brocken can emit twin streams of fire from each of his nostrils.
- Energy Beams: When needed, Brocken can fire missile-strength beams of energy from the beaks on his hands.
- Energy Bolts: Brocken can fire bolts of yellow energy from the tips of the tentacles on his shoulders. Each bolt can either create explosions as large as he or have a shocking effect much like electricity.
- Possession: Brocken can possess a human host. While possessing his host, the palm of their hands sprount a green eye and teeth. The hands can also emit a white gas from them.
|Ultraman Ace Kaiju & Seijin|
|Verokron | Yapool | Chameleking | Vakishim | Garan | Aribunta | Giron Man | Brocken | Alien Metron.Jr | Doragory | Muruchi II | Gammas | Zaigon | Alien Antira | Unitang | Sabotendar | Barabas | Ace Killer | King Crab | Cattle God | Cowra | She-Devil | Hotarunga | Black Pigeon | Android Couple | King Kappa | Zemistlar | Aprasar | Aprasar Fairy | Space Mask | Black Satan | Giant Yapool | Mazaron Man | Yojo | Mazarius | Alien Orion | Sphinx | Alien Hipporito | Lunaticks | Undergroundmon | Gitagitanga | Red Jack | Baktari | Coakes | Bad Baalon | Kaiteigagan | Dreamgillas | Soundgillar | Machless | Snowgiran | Namahage | Alien Fire | Firemons | Alien Steal | Kaimanda | Shishigoran | Iceron | Woo II | Fubigirara | Onidevil | Gasegon | Daidarahoshi | Hanzagiran | Verokron II | Yapool Woman | Univerlages | Aquarius | Alien Revole | Signalion | Geegon | Alien Simon | Jumbo King|