The Peanut Popgun (ピーナッツ・ポップガン Pīnattsu Poppugan Peanuts Popgun) is Diddy Kong's neutral special attack and is also his projectile weapon. The Peanut Popgun fires out peanuts that hit the opponent. The player can boost the speed and lower the angle of the shot by holding down the button. If the player holds the button down too long, the Peanut Popgun will explode, briefly stunning Diddy Kong, but otherwise not dealing any damage. The shelled peanuts shot out may break, dropping a small edible peanut, which will recover a small amount of damage when eaten. Interestingly, the Peanut shells fired from the popgun count as items and thus can be caught and thrown back. Also, since it is an item, the peanuts will take damage instead of following the laws of priority. If a peanut from the popgun takes 1% of damage, it will be destroyed, which makes it not as useful as other projectile attacks. The Popgun is fully charged when Diddy reaches up and grabs his hat. In order to fire a fully charged peanut without stunning the player, release the special button as soon as Diddy grabs his hat. A fully charged shot from the Peanut Popgun does considerable damage (17% worth damage), which can be useful for putting pressure on the opponent. A reflected peanut will be redirected downward based on how long the shot was charged. Diddy can cancel the move by shielding and thus, roll, spot dodge or glide toss out of this move.
Peanut Popguns were Diddy's weapons of choice in Donkey Kong 64. He would wield two at once, although his shells didn't become peanuts once he hit his opponent.
 Description from the Instruction Booklet
Press and hold the B Button to charge up for a stronger, longer shot. Don't charge it too long, or - BOOM!
 Trophy Description
A unique firearm that only Diddy Kong can use. It's made of a chunk of wood and shoots peanuts. In Donkey Kong 64, he carried two pistols and could fire two shots at a time. In Smash Bros., the peanut ammo bursts out of its shells when fired. The peanuts can be grabbed and eaten to reduce damage. The longer the gun is charged before firing, the faster the peanuts fly.