The Mecha Galgen Gang (メカ ガルゲン ギャング Meka Garugen Gyangu) is a crime organization conceptualized and used by Gallibon the Destroyer.
Most of the Mecha Galgen Gang's early history is not known exactly, but is known that the Mecha Galgen Gang was founded during the late 1970's by early members of the Mecha Galgen Gang. Many of the members of the Mecha Galgen Gang were made up of the surviving members of the Shine Shine Dan group and the Monster Clan group. The Mecha Galgen Gang is now currently run by Gevaudan, as well as being co-led by his two associates Bullets and Iron Jack. The Mecha Galgen Gang owns their own base simply known as the Mecha Gang HQ; which the location is unknown however.
Sometime later, the Mecha Galgen Gang became dormant when the Space Police and the Copdrodes began fought them off, led by Inspector Cypher. For a while, it was thought that the Mecha Galgen Gang was done for, up until Inspector Cypher himself traveled to Earth to arrest a certain squid-themed Shadowblood who was ordered to be arrested due to his crimes. Cypher was defeated however, and was left on Earth. With Cypher out of the way, the Mecha Galgen Gang resumed their work and became active again. The current leader of the Mecha Galgen Gang; Gevaudan, then traveled down to Earth (along with Bullets and Iron Jack) to wreak havoc there.
Most recently, the Mecha Galgen Gang are focused on wreaking as much terror and destruction as they can; but mainly focusing on killing their main enemy; FlamingoMask, as he always foils their plans and stands in their way. After sending in many hitmen monsters and the arrival of their scientific advisor Dr. Borg, the Mecha Galgen Gang now appear to have bigger plans in store...
- Garuma (deceased)
- Red Bat
- Gillamen (deceased)
- Bat Sister
- Zeni Crazy
- Mantis Man
- Barbe Q (deceased)
- Madam Barbe Q
- Spartans GX (destroyed)
- Mad X Airship (destroyed)
- Steamroller Robot (destroyed)
- Freezer Robot (destroyed)
- Earthquake Robot (destroyed)
- Building Robot (destroyed)
- Jumbo Mecha
- Bara Missiler
- Shine Shine Dan Fighter Jets
- Originally this group went nameless. Up until Dangan's introduction, the Mecha Galgen Gang were simply referred to as "the Robot Gangsters". Afterwards, they were called the "Mecha Gang", before then getting their official title.
- Originally the Mecha Galgen Gang were not going to be major enemies, let alone even being an actual organization. At first, the Mecha Gangsters were mean't only to be a trio of alien robot criminals (Bullets, Iron Jack and Gevaudan) in which the three would have been merely minor villains. After "Challenge of the Bullet Hitman" however they were then promoted to a much major role and were greatly expanded upon.
- They are a tribute to old Showa era organizations; chiefly being the Monster Clan and the Shin Shine Dan.
- The Mecha Galgen Gang is one of the few evil factions whose monsters aren't exactly pawns or are monsters who are officially tied with the Mecha Galgen Gang. Most of the assassin kaijins that work for the Mecha Galgen Gang are actually hired to do their jobs and can do whatever they please otherwise as they are criminals themselves; they don't have to be with the Mecha Galgen Gang all the time.
- Originally Devil Gang was going to be a member of the Mecha Galgen Gang (and most likely would have been in Dangan's place for the first monster they had to send out to kill FlamingoMask), but he was ultimately dropped.