What kind of semi-truck was the original Optimus Prime?

The leader of the Transformers' Autobots is definitely based on a flat-faced cab-over-engine semi-truck. Exactly which one, ...
Gizmodo

Optimus Prime Gets Real on eBay, Fanboys Get Wet

How is it possible to be as kick-ass as a real living superhero without actually being one? There is only one answer to this; owning/driving an Optimus Prime Peterbilt 1:1 Scale Replica, which is now ...

How Howard The Duck's Creator Enlisted An Iconic Batman Writer To Help Kill Optimus Prime

Optimus Prime's death in the animated Transformers movie was partly shaped by Howard the Duck creator Steve Gerber and ...
autoevolution

This Is the World's Only Optimus Prime Replica, a Bonkers and Most Inspiring Build

In the Transformers universe, Optimus Prime is the voice of wisdom, and the rallying force that makes machine and human alike see reason, find motivation, and come up with solutions. In the real world ...