Pumpkin Bombs are strange monsters which look like Halloween pumpkins which have come to life. They usually rely on self destructing to attack. They have been known to be items in games instead of monsters. Recently in SwoM they appeared in both of the SoM forms as well as the LoM produce item. The Godbeast Mispolm in SD3 could be considered to be a Pumpkin.
These monsters are always found paired with Blood Owls. Unlike the Pumpkin Bombs in other games these ones do not explode, they just wander around randomly.
In SoM Pumpkin Bombs are classified as Plants.
Pumpkin Bombs live in the Kakara desert and are summoned by Mad Mallards. Their main method of attack involves them casting Burst on you and self-destructing. For this reason they only give you 1 EXP for defeating them.
Nitro Pumpkin / Grenade Bomb (J)
These Green Pumpkin Bombs are found in the Cave of Courage. They do not explode like their ripened cousins, instead they rely on a few magic spells to defeat you. They like to cast Wall. On some strange occasions they have been observed to turn into Pumpkin Bombs.
Pumpkin Bombs in SD3 are throwing items used by various enemies. They deal Dryad damage and will regain some of your MP after use.
Bumpkin / Pumpkin Bomb (J)
Though no monsters like Pumpkin Bombs appeared in LoM there were many references to them. Bud and Lisa were planning to take over Domina with an army of Pumpkins which they planted in the empty field there. They use the pumpkins in some of their attacks, and they explode just like in the other games. Later Shadow Zero One would confront you in this field. The boss monster Kima would occasionally sprout pumpkins which would explode on you. The final reference to the Pumpkin Bombs was a piece of produce you could grow in your garden.