New body

It is not uncommon at all for a single Transformer to change body form many times across their life-span. The ease with which they can do so depends on the continuity's technology level. In some, changing bodies requires an extensive full-body rebuild and tends to be resource draining and even dangerous. Sometimes, however, all it takes is to transplant their brain or personality program into a compatible new body. Other times, the existing body itself will be "reformatted" on the spot using a scan of a local compatible alt-mode.

Methods

• Adaptation — As a survival mechanism, when a Transformer is stranded on an alien world a Transformer's onboard idento-computer may adapt the Transformer's body to be more compatable to the local environment. Side-effects may include extreme independance, distrust of authority figures, animalistic mindsets, and speech impediments. Generation 1 cartoon continuity

• Mechanical reconstruction — A Transformer's form is reconstructed into a new form manually through hard work, often after the Transformer is badly injured. This is sometimes accomplished by humans. Generation 1

• Unicron — This being can reconfigure other beings into super-powerful minions of his will. Generation 1

• Scanning — A Transformer has on-board systems that allow him to scan a new form himself and immediately take on the new form. Robots in Disguise, Unicron Trilogy, Movie continuity, Animated, Action Blast

• Trans-scanning is a particularly adaptable form of personal scanning. Movie continuity

• Matrix bearing — Some Transformers, upon taking possession of the Matrix, are instantly upgraded to a new body. This process reverses whenever the Matrix is not held by the Transformer. Generation 1

• Transference — A Transformer's essence (personality component, spark, or simply their mind) is transferred to a new body or into a blank protoform. Generation 1, Beast Wars, Animated

• Internal Reconfiguration Matrix — This device has allowed Optimus Prime to alter his vehicle modes. Generation 2

• Transmetal — During the Beast Wars, Transformer bodies were unintentionally altered by a quantum surge. Beast Wars

• Transmetal 2 — Transformers were altered either through a piece of Vok technology called a transmetal driver or through experimentation by Megatron. Beast Wars

• Reformatting — In Beast Machines, reformatting is the process by which a Transformer is converted to a technorganic form. Beast Machines

• Burning justice — By believing in himself, a Transformer my sometimes cause a spontaneous upgrade into a new body. Cybertron

• Off-panel — Sometimes Transformers would arrive at a new place with a new alternate mode with little explanation, but it is implied they were mechanically altered by technology aboard their ship or back at base. Marvel Comics continuity, IDW Generation 1 continuity

Fiction

Cartoon continuity

• Adaptation — While stranded by themselves on Earth, the Insecticon's idento-computers adapted their forms to be able to process plant life for energy. It is not stated how long this took, nor were further details provided. They were discovered four million years later. A Plague of Insecticons

• Mechanical reconstruction — Orion Pax and Ariel were mechanically recreated into Optimus Prime and Elita One. War Dawn The computer aboard the Ark scanned the surroundings for suitable local life-forms then physically rebuilt damaged Transformers with altmodes to blend into their surroundings. More than Meets the Eye, Part 1 After being severely injured, Bumblebee was rebuilt into Goldbug by a Quintesson. The Return of Optimus Prime, Part 2

• Matrix bearing — Hot Rod was instantly upgraded to Rodimus Prime after taking possession of the Matrix. The Transformers: The Movie

• Unicron — Unicron upgraded Galvatron, Cyclonus, Scourge, the Sweeps, and Cyclonus's Armada from wounded Decepticons. The Transformers: The Movie

• Transference — Starscream liberated the Combaticons' personality components from the Decepticon Detention Center and installed them into new bodies. Starscream's Brigade Brawl had his personality temporarily transfered into a human built robot. B.O.T.

Marvel Comics continuity

• Mechanical reconstruction — The computer aboard the Ark scanned the surroundings for suitable local life-forms then physically rebuilt damaged Transformers with altmodes to blend into their surroundings. The Last Stand The Transformers Bumblebee was rebuilt into Goldbug by G.I. Joe. ...All Fall Down! Bumblebee was rebuilt into Goldbug by Wreck-Gar. Hunters Megatron was rebuilt into tank form by Cobra. Realignments

• Matrix bearing — Hot Rod was instantly upgraded to Rodimus Prime after taking possession of the Matrix. Rodimus Prime's Universe profile Space Pirates!

• Unicron — Unicron upgraded Galvatron, Cyclonus, Scourge, and the Sweeps from wounded Decepticons. Universe character profiles Target: 2006

• Transference — The Ark created new bodies for five Autobots who had their minds encoded on crystals before the Ark left Cybertron. Rock and Roll-Out! Before he was destroyed, Optimus Prime's personality was saved on a floppy disk by Ethan Zachary. His personality was later downloaded from that disk into his powermaster body. People Power!

• Off-panel — Megatron had the bodies of the Insecticons and Coneheads adapted to forms more appropriate for Earth. Aerialbots over America! After being restored to individual robots after having been used for parts to make Circuit Breaker's Autobot suit, several of the Cybertronian Autobots apparently took the opportunity to change to Earth forms. Decepticon Graffiti! The Predacons took on Earth forms on orders from Shockwave. Gone but Not Forgotten!

The Autobots around this time period do not display the same ability to casually modify their forms. The Dinobots are often not taken on missions because their forms would stand out. This may be because the Decepticons have access to more resources from Cybertron thanks to the space bridge.