Not only can you become the longest and most dangerous worm in Sworm.io, you can create an entire swarm of them.
Steer your worm with the mouse. Left click boosts. Right click allows you to cut other worms (as well as your own). The more you eat, the bigger you'll get, and pick up shield powerups to give yourself an extra edge.
Try to fake other worms out so that you can slip in for the kill without them noticing.