Bumblebee

Peter Cullen (voice of Optimus Prime) is the only cast member to appear in every theatrically-released Transformers film. He had voiced the character in Transformers - Der Kampf um Cybertron (1986), as well as the original series and reprised the role in the live-action films, including this one.

When Bumblebee plugs into the wall socket, he plugs into the ground line. This should have had no effect.

SPOILER: There is a mid-credits scene: Bumblebee reunites with Optimus Prime in a forest as more Autobots arrive and Charlie finishes fixing the Corvette.

Although the original British submission was uncut and rated 12A, it was replaced by a cut PG version removing 6 seconds of violence/injury.

Featured in Orbit Report: Will The Bumblebee Movie Be Good? (2018)