Transformers use these modes as disguises in order to conceal themselves from the human population. Most of the popular vehicle modes are cars, trucks, jets, tanks, etc. The part that allows them to transform into their alt modes is the T-Cog.
Scanning new alternate modes whenever the mood struck was not a privilege all Cybertronians enjoyed prior to the toppling of the caste system, some in fact took pride in retaining only one alternate mode throughout their lifetime.
Transformers rarely had alternate modes when they first arrived on Earth and would scan a new mode, usually from whatever vehicles were nearby. Megatron and Shockwave retained their Cybertronian alternate modes.
After scanning an Earthly vehicle and reformatting accordingly, Smokescreen referred to it as his "v. mode"
Soon after arriving back on Earth, Bumblebee refused to allow the exposure of Cybertronian vehicles and made Strongarm and Sideswipe scan Earth alternate modes. Bumblebee by contrast had retained his Earth mode even while on Cybertron.
Known Alt Modes
- Vehicle mode
- Beast Mode