Marimo

Marimo are the easiest living thing you will ever own. A soft green ball of algae that sits in a jar of water, grows about 5mm a year, and asks for a water change every fortnight and very little else.

No soil, no light rig, no feeding. Good on a desk, good for kids, and startlingly hard to kill. Ours are grown and kept in Brisbane, and each one comes with a care card that fits on the fridge.