Acid pellet

Prowl brought urine to a gunfight. No wonder Scavenger wasted him.

Acid pellets are small projectiles formed of acid. The Autobot Prowl uses a gun that is capable of firing acid pellets, as well as lasers. Scattershot wields an automatic acid pellet gun, which is also used by Computron. A burst from Scattershot or Computron will burn you. Up to 500 times per minute. Doubleheader's Pretender shell, not as much with its semi-automatic acid pellet pistol. In some continuities, Warpath uses a similar weapon but on a larger scale; Acid shells.

Fiction

Marvel Comics continuity

Marvel The Transformers comics

During a confrontation between the Terrorcons and the Technobots in the Nebulan city of Splendora, Computron blasted Abominus with his acid-pellet gun while berating the Decepticon for being too dim-witted to understand what was happening. Love and Steel!

Regeneration One

On a Cybertron overrun with shadow-leeches, Kup found Scattershot's acid pellet gun outside the Star Chamber and used it to pierce through the door, much to the consternation of Ultra Magnus. The War to End All Wars, Part 5