Totally Nuts

Totally Nuts is the fourth level of I, Zombie in Plants vs. Zombies. Additionally, it is present in Plants vs. Zombies: Journey To The West.

Strategies
Use Ladder Zombies to climb over Wall-nuts. They also are immune to Snow Pea's freezing effect when still holding their ladders, so use them there too. A single Ladder Zombie can also survive in a row with a single Peashooter or Snow Pea (if it is placed directly next to Wall-nuts), even without its ladder. Since the Ladder Zombie's shield does not protect it from Fume-shrooms, use Buckethead Zombies instead where they appear. If there is only a single Peashooter and no other offensive plants in that row, a Buckethead Zombie can survive, regardless of where the Peashooter is in the lane. If there are two Snow Peas in one lane, send a Ladder zombie to climb over the Wall-nut and another one to block the freezing effect.

If you want to save sun, in the lane with Fume-shrooms, send a Buckethead Zombie and another one when the Wall-nut is eaten, by then the bucket should have fallen off. Do not send them both as once, as Fume-shroom's fumes will damage both zombies.

Trivia

 * This level is the first I, Zombie level in which Ladder Zombies can be used.
 * Fume-shrooms always appear on the left two columns in the third row.
 * Wall-nuts always appear on the column closest to the red line.