Hatch or Steal: Online - a pet farm that can be robbed
You buy eggs, hatch them into pets and put them on the farm. Pets bring money, and the farm earns money even when you are not in the game. There are up to six people in one arena, and each has their own farm. Other people's pets can be stolen, and yours can be taken away too. You can lock the farm, and catch the thief and hit him with a baton.
The money is spent on improving the farm and speed training. Rebirth provides permanent bonuses, and a portal leads to the dragon's lair. There you need to go through an obstacle course, like in obby, and pick up a rare egg. In total, the game has more than 40 pets and 8 levels of egg rarity. If you prefer to just build a business and earn money, without stealing, check out ObbyTycoon: Money Tycoon.