Kingdom Rush

J.T. is the giant Yeti that appears during Wave 19 on the 9th level of the campaign, "Stormcloud Temple". To unlock this achievement, all you need to do is Kill J.T. Once J.T. is dead, the level will end.

J.T will appear at the top of the map (the north spawn point) and will slowly make his way towards the objective in the middle. Throughout the wave, other enemies will continue to spawn, so be sure to keep your defenses up and active. The one other thing to watch out for, is J.T will occasionally slam the ground and freeze a few towers near him. You'll need to click A 3 times on a frozen tower to unfreeze it. It can get a little hectic, so just keep an eye on them and unfreeze them as fast as you can. I killed J.T using a mixture of Level 4 Mage Towers and Archer Towers in the middle area of the map. Adding in Barracks and using the fireball power with the Left D-Pad are also great ways to slow him down and chunk his health.

If you're having trouble or have any questions, please feel free to ask and I'll try to offer any additional assistance I can provide!