CO2 soda gun

Pepsi Convoy wields a mighty CO² gun. It may well operate by the awesome power of diet Pepsi and small chewy mints. Probably, however, it does not.

And on the rare occasion he can't scream his enemies into submission, Siren also packs a sawed-off CO² shotgun, which shoots high-powered, frigid bursts of CO², freezing his enemies in their tracks.