Two kinds of food
The listing gives two meals: plants, and other cells. Other cells include players. Plants are the meal that the description does not say will hunt you back. A hunt only helps if you are the one who finishes it.
Pick a distance before you commit
Player-reported parts assume a distance. Drills, leech mouths, jaws, and zappers are described for close fights. Tentacles are described for starting farther away. Flagellums, a stinger, and a poison sac are described for leaving. If you have none of those yet, eat plants and dash with Space.
If you have the mythic Void, one player says it replaces that dash with a teleport about every 12 seconds. See the mutations guide.
Giant bosses
The official text says you grow huge and take down giant bosses. It does not name them, list phases, or give a size requirement. Build a body you can pilot, then fight a boss when the game presents one. There is no published attack chart.
A 16-player server means other people can be the closer threat. Bosses do not replace that.
The short record is Giant bosses.