Peashooter

The Peashooter is the first Plant the player will unlock in Adventure Mode. He costs 100 Sun to plant. He shoots peas at Zombies, damaging them and continuing to attack until they die or fall out of his range.

Peashooter can be found on Page 1, Seed 1, having a  limit of 3 

He is based on his appearance in Plants Vs. Zombies, functioning identically to how he does in Plants Vs. Zombies Adventures.

Strategies
Peashooter is your first ever attacker in the game, which also means your first line of defense too. Shooting a singular pea at zombies will for sure prove to be useful against the many zombies that'll show up in the game. Don't get too attached to Peashooter however, you'll get much better attackers sooner or later. Later Levels, this poor mate will be worn out by many threats. Try replacing him with Aspearagus, Snow Pea, and Repeater whenever you happen to unlock them at some point. They'll prove to be much more useful.