Snake shoots a shot that resembles a snake head. When it lands, the snake will start "slithering" randomly on the map, exploding every so often when it does so. On a lucky shot, the snake can go straight down, continuously dealing damage to the victim.
The biggest of them all, although pythons are bigger in real life. Cobra is the largest in size when compared to the other upgrades and slithers the longest. However, it may decide to turn around suddenly and head to sky, not dealing much damage at all.