Cob Cannon

Cob Cannon is an upgrade plant which can be purchased from Crazy Dave at his shop and must be planted over two side-by-side Kernel-pults, which must be placed one in front of the other in the same row, horizontally. They are the only plant in the entire game that take up two spaces.

The Kernel-pult is clearly based on the Corn.

Powers
The Kernel-pult's main power is to fire a deadly cob.

Plant Food recharges the cob if it isn't recharged yet and launches a fire cob.

Trivia

 * It takes exactly 36.41 seconds to give out a new corn cob.
 * In games such as Plants vs. Zombies 2: It's About Time and Plants vs. Zombies 5: The Adventure Continues at Sea!, it's not a upgrade plant.