Snail Blaster

Snail Blaster (known as Den-Den in Japan) is a snail-shaped Badnik (hence its name) that appears in Launch Base Zone in Sonic the Hedgehog 3 for the Sega Mega Drive.

Attack Pattern
Snail Blaster will stick to the walls in Launch Base. When the player approaches, it will open its shell and fire energy balls out of two hidden cannons - at 45 degrees above and below horizontal. After this it will close its shell again.

It can only be destroyed while the shell is open, and is otherwise invulnerable.

Sonic the Hedgehog OVA
In Sonic the Hedgehog: The Movie, Snail Blasters ambushed Sonic, Tails, and Knuckles while they were hurrying to Robotropolis to stop a machine (which Dr. Robotnik gave instructions to destroy it). Knuckles destroyed them while Sonic and Tails kept going.

This version of Snail Blaster was based on concept drawings and not its Sonic 3 sprites.

Trivia

 * In Sonic OVA, Snail Blasters could move up and down the walls in Robotropolis. In the game, they couldn't.