First appearance: IPTSF Text 36
'Peashooters' are an unnamed type of plant unit that were seen defending the Haffaton city of Diecast. They are archer units that spit green projectiles at their enemies doing roughly 1d6 damage. Until they reared up to attack, they were indiscernible from the overgrown garden they were part of.
It seems likely that they always have zero move.
Real World References
They appear to be somewhat reminiscent of a certain computer game that involves plants and zombies being at odds with each other.
They also have a striking visual similarity to the Pokemon Bellsprout.