This fuRo Core personal transport from the Chiba Institute of Technology is 6'6″ and 507 lbs. Core developer Takayuki Furuta suffered from spinal cord disease when he was younger and was inspired by Astro Boy to study robotics.
This Core can carry up to 220 lbs. and resembles everyone's favorite police enforcement mecha, ED-209. You can check out more robotic walkers from Furuta (who eventually recovered from his spinal affliction) at Plastic Pals.