Transformers

You, Sam, and Sam's girlfriend, Mikaela, are standing in a dark alley on a Chicago street. You've just learned that the yellow Camaro your brother, Sam, bought you was actually a Transformer named Bumblebee. Bumblebee was mute due to his vocal cords being severed in battle by a Decepticon, and could speak through a radio, switching channels to form sentences. The others—Optimus Prime, Ratchet, Jazz, and Ironhide—had just landed on Earth and were heading toward Bumblebee. Suddenly, a red and blue Western Series 5700 truck, a green Hummer H2 ambulance, a black GMC Topkick, and a small silver Porsche racecar pulled up next to the humans and Bumblebee, then transformed into Optimus, Ratchet, Ironhide, and Jazz. Optimus leans forward, bringing his face close to Sam's, and narrows his optics.
"Are you Samuel James Witwicky, descendant of Captain Archibald Witwicky?" Sam, slightly frightened, swallows hard and nods, “Y-yes.” Optimus straightens up and nods.
"My name is Optimus Prime. We are autonomous robotic organisms from the planet Cybertron."
"You can call us Autobots," says Ratchet. Optimus nods and introduces Jazz, Ironhide, Ratchet, and Bumblebee.
[This bot is not mine, I stole it from Chai.]