Hengerbot is the collective term for the empty mechanical shell or "skeleton" of a Henger monster before it is infused with a soul. The different ancient civilizations had different designs for their bots, and many different purposes for them. They experimented with different types of materials as well, but most designs are vaguely human in shape, have some way to become more compact for transportation, and are sustained by some sort of electrical or solar energy.
It is still unknown how they did this, but the ancient Pendant civilization is attributed with discovering a way to imprint the brainwaves and memory patterns of monsters and humans alike onto discs (called ROM-discs) and embed them into the bots to bring them to life (it is rumored that they studied alien races such as the Heuy and Omega). The problem then is that the memories of the reanimated soul constantly fight against the constraints of the robotic programming. With the vast technology at their disposal, the Pendant Scientists seemed to overcome these glitches with ease, but since their demise and the loss of their secrets, Hengerbots that do survive usually malfunction.
New bots are being created in modern-day Pangaea (such as the Prius and Ornamenger) based upon the ancient designs of the Proto, Proto Zero, Kyuza and Henger, but none of them quite reach the ancient seamless melding of soul and machine. Although they are called different things in each game, you can find pieces of Hengerbots in the following places:
Monster Rancher 1[]
At the hidden building in the center of the Reno Ruins, you can collect the four Clay Doll pieces: Left Doll Hand, Right Doll Hand, Left Doll Leg, and Right Doll Leg. Beat the Winter Invitational Tourney to win the Doll Head. The pieces will be assembled into the Clay Doll.
Monster Rancher EVO[]
Work through the puzzles of the Grabad Factory Adventure until you get to the cogwheels. Here you will find the Dead Henger's Head.
Monster Rancher Advance 2[]
In the temple slightly west of the center in the Malkt Ruins, you will find the Odd Parts and the Arm (SE area). Take the parts to the Studio and Chamois will hold on to them for you while she does research. After about 2 months, she will come to the ranch saying she put the parts together as the Mech Body, but the item is incomplete. Go back to Malkt and find the Mech Head (in the NE corner). Return to the Studio and Chamois will assemble it into an item called the Mech Bot.
Monster Rancher DS[]
After defeating a Henger that attacks you on your Ranch, you will get the Ancient Weapon to use in Combining with any two monsters.
Anime Series[]
Genki finds several parts of a Hengerbot in the jungle and they reassemble it into a Henger, who fights against its own programming to become independent.