Made by Tomy, 1979.
"The object is to turn the terrible tank toward your opponent by shooting steel balls at the tank. If you time your shot correctly, the tank's scary revolving nose will turn and head toward your opponent. But if you miss, it'll turn on you. That's the way the terrible tank turns, back and forth until one player gets the upper hand. The tank keeps coming relentlessly until it knocks your gun or your opponent's gun out of commission. Requires two "AA" batteries, not included. It's a two-player game that's fun at every turn for tank commanders 6 and up." (from a 1979 brochure).
What's it worth? Take a look at this Turn The Terrible Tank price guide: sold listings for a value indication.