Catapult Zombie

The Catapult Zombie is a zombie in Plants vs. Zombies that rides a vehicle that rolls onto the player's lawn, destroying plants and occupying the first two columns from the right. It then stops its vehicle, and starts lobbing basketballs at the last plants (closest to the house, or the chimney on the roof) in his row. Once this zombie kills a plant, it moves forward slightly and continues attacking the next plant. When it runs out of basketballs, or if it kills all of the plants in the row, the Catapult Zombie drives towards the player's house in a fashion similar to that of a Zomboni. In the process, its vehicle will squash any plants it comes into contact with (except Spikerock). It is the 22nd zombie encountered in Adventure Mode.

Suburban Almanac Entry
 CATAPULT ZOMBIE 

Catapult Zombie operates heavy machinery.

Toughness: medium

Special: lobs basketballs at your plants

Of all the things Catapult Zombie could launch with his catapult, basketballs seemed like the best and most obvious choice.

Overview
The Catapult Zombie absorbs 33 normal damage shots and its appearance changes upon an absorption of 15 and 29 normal damage shots, where it begins to vibrate. After 33 normal damage shots, the front bumper of the catapult shows damage before exploding.

Appearances

 * Adventure Mode: 5-6, 5-7, 5-9, 5-10
 * Mini-games: Dr. Zomboss's Revenge
 * Puzzle Mode: Last Stand: Roof, Last Stand: Endless
 * Survival Mode: Survival: Fog, Survival: Roof, all Survival (Hard) and Survival (Endless) levels
 * Co-op Mode: all Co-op Hard levels, Co-op Zomboss, Co-op Endless
 * Others: Versus Mode

Strategies
Use Spikeweed and Spikerock to pop the tires, and if you don't have one available, use Umbrella Leaves to knock the basketballs out of the way while your offensive plants take care of it with it. Keep in mind that you can't use Spikeweeds and Spikerocks in any roof level. This is a good idea if you have any expensive plants like Twin Sunflowers or Cob Cannons in the back. Keep in mind that if you plant a Spikeweed or Spikerock beneath the back tire of the Catapult Zombie's vehicle it will not kill it; it appears to be steel. You also shouldn't plant any non-instant kill plant other than Spikeweed or Spikerock in the first two columns to the right if there are Catapult Zombies in the level, because it will kill them when it's approaching. In Survival: Endless, the Umbrella Leaf is a must because any Spikeweeds or Spikerocks you have previously planted will quickly be destroyed by the hordes of stacked Catapult Zombies, Zombonis, and Gargantuars. Magnet-shrooms are useless against it even though the machine is made out of metal, but you can use any freezing plants such as the Winter Melon, Snow Pea, and Ice-shroom to slow down the Catapult Zombie. Also if you don't have an Umbrella Leaf you could also use a Wall-nut behind your Sunflowers so the other plants can focus on killing the Catapult Zombie.

Note: Pumpkins are useless for directly defending plants against it, because the Catapult Zombie aims for the plant inside the Pumpkin first before they go for the Pumpkin.

Trivia

 * It has 20 basketballs. After it throws them all, it will move towards the house or chimney, crushing any planted plants along the way.
 * Its catapult is the only thing in the game that has limited ammo.
 * It takes the Catapult Zombie six basketballs to destroy a plant.
 * Unless the plant in the last space is a Spikeweed or Spikerock (in which case it is ignored), or it is in a Pumpkin, Tall-nut or Wall-nut, in which case it takes many more basketballs.
 * The Catapult Zombie's health is on the high end of the zombies with "medium" toughness, with the Digger Zombie's being at the low end.
 * Although it has higher health than most plants, the Garlic only takes six basketballs before dying, the same as any other plant being eaten (other than defensive plants).
 * Apart from the Digger Zombie, the Catapult Zombie is the only zombie to attack the plants in reverse order (until it runs out of basketballs).
 * If there are no plants in the Catapult Zombie's row, it will drive towards the house or the chimney while crushing any newly planted plants.
 * The Catapult Zombie, the Zomboni, the Zombie Bobsled Team (on ice), and Dr. Zomboss are the only zombies with vehicles.
 * Killing one produces another one. Avoid using an instant kill on the same row it's on or a row next to it.
 * On the home page of the official Plants vs. Zombies website, the Catapult Zombie is seen holding a sign saying, "Try the Zombatar!", not riding its catapult vehicle, and wearing glasses.
 * The Catapult Zombie, the Digger Zombie (while digging), the Ladder Zombie, the Gargantuar, the Giga-gargantuar, the Zomboni, and the Balloon Zombie (while on its balloon) are the only zombies that can get past a Tall-nut by itself without eating the plant.
 * If a plant is planted below the Catapult Zombie, the plant will be immediately be squashed.
 * This does not include Spikeweed or Spikerock, in which case it would pop the tires of the Catapult Zombie instead.
 * When the Catapult Zombie is frozen or paralyzed, the vehicle has the inability to crush plants. This is probably a glitch.
 * There's quite a resemblance between a Catapult Zombie's head and a Digger Zombie's.
 * There is an oil stain on the Catapult Zombie's left cheek.
 * It is unknown how a new basketball transfers from the basket of the machine to the catapult after the old one has been lobbed without any animation of the Catapult Zombie or any other Zombie taking a ball from the basket and placing it in the catapult.
 * Possibly the catapult has a mechanism that automatically transfers a new ball to the catapult after the old one is used.
 * This cannot be true though, as no such mechanism is visible.
 * Even if there was probable evidence of such a mechanism, it still would not explain how a new ball literally teleports into the catapult bypassing such a mechanism entirely and thus defeating its purpose.
 * The same thing happens with the projectiles of the lobbed-shot plants (except Cob Cannon).
 * When seen without its Catapult, the Catapult Zombie appears to have a small dirty rag hanging out of its back pocket. There is no further reference or clues as to what it uses its rag for. It may use it to clean its Catapult and its parts.
 * The Catapult Zombie appears to be a little overweight. This may be due to the fact that it is riding around in a vehicle almost all of the time.
 * However if this was the cause for its weight then a Zomboni would look like it weight-wise.
 * The Catapult Zombie's speed is same as a flying Balloon Zombie's.
 * This zombie is an opposite of the Carrot Launcher, as both shoot the last plant/zombie in the row.
 * If players look closely, they can see it uses a basketball hoop to lob basketballs.
 * The player could also see that it is a basket that holds the basketballs.
 * It is similar to the Archer Zombie