Slime molds are another excellent model for studying cheating. They're typically single cell organisms except when starved. Then they chemotax an aggregate into a multi-cellular organism. At this point they undergo sporulation, producing a stalk and a fruiting body. Cells in the stalk die while those in the fruit are hopefully whisked to greener pastures. When the slimes are homogeneous this works just fine. In a heterogenous setting all bets are off.

Cheater mutants have been widely observed and fall into two categories: obligatory and opportunistic cheaters. The obligatory cheaters refuse to participate in the stalk, while the opportunistic cheats preferentially segregate themselves into the fruit. It's easy to see how these behaviors might be beneficial. There's a double edge to obligatory cheating, though: in they cannot undergo sporulation.