User Dave, the vapours are no longer considered a real ailment. But I believe Fume-shroom will be of use here. His vapors are quite real and provide a distinct advantage against the right zombie opponents.
The Jester Zombie can ruin a player's strategy if they do not bring the right plants. Jester Zombie deflects projectiles like Peas and lobbed-shot projectiles, so the player must bring plants that don't use projectiles to defeat it. Penny at the beginning of the level shares dialogue that will aid the player if they so happen to read it. The newly acquired Fume-shroom can easily deal with the Jester Zombie, as well as other plants like Snapdragon or Laser Bean. Necromancy is the other big threat in this level, which can get Conehead Peasants deep into defenses.
The small number next to the zombie icon means that zombie will always appear in that lane, with 1 being the topmost lane and 5 being the bottommost one.
500%/7 Plant Food, two normal and one sun-on-destruction tombstones are created
First flag, Necromancy!
400%/7 Plant Food
Two normal, one sun-on-destruction, and one Plant Food-on-destruction tombstones are spawned
600%/7 Plant Food
Start off with two columns of Sun-shrooms. Use Grave Busters to remove graves and Puff-shrooms to kill the typical zombies. Get ready for an ambush.
Quickly plant one column of Wall-nuts or Tall-nuts. Do not forget to plant one column of Laser Beans or Snapdragons behind Wall-nut or Tall-nut and two columns of Fume-shrooms. Necromancy-spawned Imp Monk Zombies will be of no threat.
When a Jester Zombie comes, avoid using plants that throw projectiles, unless they can hit Jester Zombies by whatever means.
Use Cherry Bomb when necessary and keep using Grave Buster to remove spawned graves.