Blaster, called Pon-pon (ポンポン) in the Japanese manual, is a Badnik from Sonic & Knuckles found trundling around in Flying Battery Zone. They appear to be based off of a Hercules beetle, and fire small projectiles at the player from their horn-like cannon, which harmlessly bounce off any shield type. A simple jump is enough to permanently dispatch them.
They resemble the Blastoids found in Hydrocity Zone and behave in the same manner.
They return in the Wii U/PC version of Sonic Lost World where they appear exclusively in Desert Ruins Zone 2, but with a different design and attack pattern: they move backwards on the mach-speed routes of the stage and, instead of shooting projectiles directly at Sonic, they shoot honey at the screen, temporarily obscuring the player's vision.
They also return in Sonic Mania, found in Flying Battery Zone again and returning to the original attack pattern from Sonic & Knuckles.