Fumes are a purple cloud of spores produced by Fume-shrooms and Gloom-shrooms. Each cloud of fumes deals one pea of damage but hits everything within it, i.e. everything that the fume-producing plant can shoot at the time, making it an area-of-effect attack. Gloom-shrooms fire four times faster than the Fume-shroom and as fast as a Gatling Pea. The Fume-shroom hits the four spaces in front of it, while the Gloom-shroom hits all eight squares around it.
Fumes are renowned for their ability to pass through shields, namely screen doors, newspapers, ladders, and trash cans. While lobbed-shot plants can also circumvent shields, fumes, unlike lobbed-shot plants, also damage the shields, making them slightly more effective given the same damage per second if there are non-fume and non-lobbed-shot plants as well as the shield will be destroyed faster, and if the zombie is not already dead, these other plants will be able to contribute against the zombie.
Their sound and behavior are closer to liquid than a gas.
Fumes, following to the dictionary, are toxic vapors, explaining why they go through shields. This does not explain their decapitating and damaging effects, however, though it may be due to the fumes deteriorating any material it comes in contact with, like metal shields or rotting zombie skin.
Fumes are the only non-lobbed projectiles that ignore the roof's angle.
The Fume-shroom attacks all zombies in its range, damaging all zombies that are touched by the spores.
Fumes are the only area of effect projectiles that do an equal amount of damage to every zombie in range.
In the Plants vs. Zombies 2, fumes have a noticeably different appearance from spores.