Cattail (PvZ)

Cattail is a plant in Plants vs. Zombies. It attacks zombies by firing homing spikes at the nearest zombie to the house.

It is an upgrade for the Lily Pad and becomes available to purchase before playing Level 4-5. It costs $10,000 to buy from Crazy Dave's Twiddydinkies and 225 sun to upgrade Lily Pad in the Pool. It fires two spikes at the same speed of a Repeater and can pop the balloons of Balloon Zombies, who it prioritizes over all other zombies when they are still airborne.

Suburban Almanac entry
Cattail 

Cattails can attack at any lane and shoot down balloon zombies too.

Must be planted on lily pads

"Woof!" says Cattail. "Woof woof woof! Does this confuse you? Do you expect me to say 'Meow' like a cat because the word 'cat' is in my name and I also look like a cat? That's not how things work around here. I refuse to be pigeonholed."

Cost: 225

Recharge: very slow

Strategies
Because a single Cattail can cover all six lanes and have the damage and rate of fire of a Repeater, it makes a good early defensive plant. It also prioritizes Balloon Zombies and helps deal with Digger Zombies and Imps. However, they are easily overrun because of the ability to cover all six lanes and the priority of targeting the zombie closest to the house. A Cattail may be targeting a Conehead Zombie, then a Pole Vaulting Zombie that is closer to the house draws its fire, letting the Conehead Zombie go on unhindered. Also, all of your Cattails will typically fire at the same target (except under certain conditions) and when that target dies, spikes in the air are wasted. This limits the effectiveness of large numbers of Cattails, so it is recommended that you do not rely solely on Cattails for defense.

It is a good idea to use Cattails in large numbers in Survival Mode that take place in Pool or Fog, as they do well against Balloon Zombies. Do not forget to back them up with more consistent firing plants, such as Repeaters or Melon-pults.

Cattails can be very useful in large numbers as they can destroy zombies rather quickly and will be able to save space in other lanes. However, the fact that they are only available in Pool and Fog limits their utility.

Trivia

 * Its leaves' filenames in the game are Cat_paw1.png, Cattail_paw2.png, and Cattail_paw3.png.
 * It is the only upgrade plant that is aquatic and is also the only offensive upgrade plant that upgrades from an unoffensive plant. It is also the only aquatic plant that needs to be planted on Lily Pad.
 * It can be downgraded to a Lily Pad if the player has a Pumpkin on it and tries to dig it up, as that would cause the Pumpkin to fall into the water otherwise. Bungee Zombies can also downgrade it with a Pumpkin. This makes it the only plant to be able to downgrade.
 * It is the most expensive aquatic plant, costing 225 (25 extra for Lily Pad) sun with a 250 sun  total. However, this value can rise in Survival: Endless due to the increasing price of upgrade plants.
 * During the ending credits of Zombies on Your Lawn, it is shown next to Laura Shigihara's name. She says it is because it is her favorite plant.
 * When a zombie is defeated, the spikes from Cattails are still aiming for the same direction, it will not damage the zombie behind the defeated one (unlike some other projectiles, which hit the zombies at the back).
 * Its spikes move slower than Cactus'.
 * It and Lily Pad are the only aquatic plants that can have a Pumpkin on them.
 * Its spikes on the Nintendo DS version of the game will sometimes miss the zombies, and keep circling it until it dies, as well as not target zombies, but rather fly straight ahead and rotate slowly.
 * It has the longest range among the shooting plants.
 * It can fire in the most directions. The plant that fires in the second most directions is Gloom-shroom (eight) and the third is Starfruit (five).
 * Despite the fact it can pop Balloon Zombie's balloon, Cattail is not listed as a weakness of Balloon Zombies in the Suburban Almanac entry.
 * It will not aim at a Snorkel Zombie when it's underwater. However, it can fire anywhere on the screen and will aim at Balloon Zombies. This is possibly because it cannot see it. It may also be because it cannot fire at it as the Cattail might not be able to fire heights that low.
 * When a Cattail is targeting a Pole Vaulting Zombie and the zombie vaults, the spikes will act as it would if the zombie already died, but when the Pole Vaulting Zombie lands, the spike will turn around and attack the zombie again.
 * This also happens when a Balloon Zombie loses its balloon or when a Dolphin Rider Zombie loses its dolphin.
 * In the mini-game Heavy Weapon, its tail is pink instead of brown.
 * It can support a Pumpkin even though the Pumpkin looks like it is floating.
 * This is because it is an upgraded version of Lily Pad, and Lily Pad's function is to support plants on water.
 * The player cannot plant a Cattail on a Lily Pad occupied by a plant besides a Pumpkin on it.
 * If it is planted in the very front rows, its spike cannot home into zombies.
 * It will not attack unless there are zombies in the second column or farther.
 * In some versions, when a zombie targeted by a Cattail is not killed by it, the spikes fired targeting the dead zombie may circle around the dead zombie's death location. This behavior has been seen in the most recent Android update.
 * It has a counterpart in Plants vs. Zombies 2, which is the Homing Thistle. The only difference between the two is that Cattail fires 2 spikes dealing 1 normal damage shot each, while Homing Thistle only fires a spike, but dealing 2 normal damage shots each.
 * It seems to act like a normal plant on a Lily Pad, as they cannot plant anymore plants on it and it can support a Pumpkin.
 * Even if it can hit zombies from the back, it will still damage Screen Door Zombie's screen door, even if the projectile hits Screen Door Zombie's back.