You're going to want this controllable Battle Robot for Minecraft 

Everyone loves mechs, especially battle mechs you can control with weapons such as a Tank Buster Torpedo Launcher. Now, you have your very own in Minecraft.

Created by Cubehamster, Mega Gargantua is a controllable battle mech you don't need any additional mods to use.

Players will hop inside to manually control Mega Gargantua and to use weapons such the aforementioned Tank Buster Torpedo Launcher along with the A02 Front TNT Cannon, Sequential Tomahawk Missile Launcher, and others.

If you have 60 hours to spare you can build it yourself in Survival Mode.

A video of the mech below and you can look over the features and find the download link for the robot through Planet Minecraft.

Thanks, PC Gamer.