Perceptor is my favorite transformer:
"Perceptor was an Autobot scientist, specialising in metallurgy, who transformed from a robot to a microscrope. When transforming to microscope mode, he could, but did not need to, revert to a smaller size. In microscope mode, Perceptor's lens barrel could function as a powerful microscope, a telescope or a light cannon. Perceptor could also use his light cannon/lens barrel in robot mode. His greatest trademark in all the series was his ability to overanalyse nearly every situation. Given these talents, Perceptor was an extremely valuable asset to the Autobot cause."