Stunion

Stunion is the fourth plant obtained in Frostbite Caves in Plants vs. Zombies 2. He is a single-use plant and when zombies get close to him, he releases a cloud of gas in a 1x2 area in front of himself, similar to the one emitted from a zombie defeated by Chili Bean, stunning the affected zombies for 12 seconds. The gas cloud does not affect mechanical enemies, except for Zombie Bulls, Gargantuar Primes, Yeti Zombie, and Bug Bot Imps.

Origins
Stunion is based on the plant Allium cepa, also known as the common onion in English. He is usually used as an ingredient in cooking, thanks to its distinctively pungent taste and aroma. His name is a portmanteau of "stun," an act of driving someone into an unconscious or semi-conscious state, and "onion," the plant him is based on.

Almanac entry
Sun cost: 25

RANGE: Close RECHARGE: Sluggish

Stunions breathe a stunning cloud of gas on nearby zombies in the lane.

Usage: single use, activates when zombie is close

Special: stuns nearby zombies

Oh sure, everyone knows Stunion as the battle-hardened warrior with the potent breath. But he's so much more than that. He's an accomplished pianist. He speaks five languages fluently. Heck, he's the leader of a Cub Shallots group in his spare time. Dude's got layers. Go on, peel 'em back. You'll see.

Plant Food effect
When fed Plant Food, Stunion will release a burst of gas in a 4x3 area in front of him, stunning all zombies in the said space for 18 seconds.

Costumed
Stunion now releases a burst of purple gas in a 5x3 area in front of him, stunning affected zombies for twice as long.

Strategies
Compared to Iceberg Lettuce, Stunion can stun all zombies in its area of effect instead of just one target. The stunning effect is not nullified by fire-based plants and also works in Frostbite Caves, where Iceberg Lettuce can only slow instead of stop enemies. However, Stunion does not work on mechs and costs more sun than Iceberg Lettuce. In most cases, though, its slightly bigger price will not matter. On the other hand, its Plant Food effect is significantly worse—while Iceberg Lettuce's plant food ability affects the entire screen, Stunion's plant food ability only affects a limited area.

Stunion is a good choice against Chicken Wrangler Zombie and Weasel Hoarder, as it can stun them and prevent them from releasing chickens or weasels, even when they are defeated.

In Dark Ages, Stunion can be used to prevent Jester Zombie from reflecting projectiles. However, the same is not true for Parasol Zombie and Excavator Zombie in Lost City, as they can neutralize projectiles even when stunned. If using Stunion against MC Zom-B during rap, make sure to plant it on the square that MC Zom-B is on or the one in front, otherwise MC Zom-B can kill it with its microphone which has longer effective range.

Stunion should not be used in tandem with Primal Peashooter, as the latter's knockback will remove the stun effect, rendering Stunion useless. Iceberg Lettuce should be used in this situation instead, since its freezing effect is not interfered by Primal Peashooter.

Stunion also works well with Primal Potato Mine since he stops the zombies whilst the Primal Potato Mine arms, creating a cheaper Cherry Bomb.

Trivia

 * It can stun flying zombies, unlike Iceberg Lettuce and Chili Bean.
 * When it disappears, it makes the same sound as Puff-shroom when dying.
 * If it stuns a zombie and that zombie dies before the effect is gone, the zombie's body will just remain there, standing still until the stun effect ends and the body collapses. The gas cannot be seen.
 * If a stunned zombie is pushed back by Hurrikale and lands up on a slider tile, it will remain there until the gas disappears.
 * Its tongue is green, as seen whenever it opens its mouth to stun zombies.
 * It and Chili Bean both use the same gas to stun zombies. They are also the only plants able to do so.
 * Apple Mortar can also stun zombies, but for a very brief period of time.
 * For a brief moment after stunning, it can be shovelled for sun.
 * This is similar to Ghost Pepper, which can be shovelled for sun briefly after exploding.