Most of Optimus Prime's appearances in animated productions and their respective toys have had his alternate mode as the Freightliner semi-truck or a fictional truck of visual similarity ...

Optimus Prime is one of the most popular and highly rated buildable models in the Lego Icons lineup--for good reason, too.

Incredibly, like the original toy, the Lego robot also transforms into the tractor half of a semi truck. The Lego Optimus Prime is comprised of 1,508 pieces and stands 13.5 inches tall in robot form.

Robosen Robotics' Optimus Prime robot can automatically transform into a truck just like the movie/cartoon versions, but the breathtaking $900 price makes it more a toy for collectors than children.

Self-transforming Optimus Prime is back with a new transforming trailer as well. The self-transforming Optimus Prime, which could transition from a truck to a robot, is now back.

Attention Autobots: Optimus Prime is in Dothan and he is waiting. OK, so it’s not the Transformer big guy himself, but rather a Western Star truck used to represent Optimus Prime in the movie ...

Incidentally, there's a somewhat popular secondary theory that the original Optimus Prime toy's alternate mode was actually inspired by the Kenworth K100, another semi-truck with the flat-faced ...