This is a video of the 1:2.5 scale World War II era M26 Pershing tank built by high school student and Youtuber MacroMachines over the course of fourteen months. It looks pretty sweet. It's hard for me to imagine there are kids still in high school that out there building driveable scale-model tanks. When I was in high school I wasn't doing that, I was...wait -- what was I doing? "Failing all your classes?" Haha, yeah...except home ec -- we didn't get grades that semester because I set our classroom kitchen on fire baking brownies during an exam.
Keep going for the video, but skip towards the end if you just want to see him patrolling his yard in the thing. Now it just needs a functional cannon. Also, if you're really interested, he has 24(!) other build videos of the tank being constructed.
Thanks to Cliff S, who agrees he needs to add some firepower to that thing and lay siege to a neighbor's house.