Mutant plant

The Sims
In the orginal Sims, a very similar plant to the mutant plant makes an appearance called "Cytherea Asilus Casses" and is possibly another variation of the Laganaphyllis Simnovorii (Cow Plant) from The Sims 2 University. The plant can only be placed on counters and only requires food after the first sim day.

The Sims Bustin' Out
The mutant plant makes its appearance in the The Sims Bustin' Out for the console only, and can also be seen in the original trailer for the game. Although similar in appearance to the Laganaphyllis_Simnovorii, it is prehaps a reletive as it does have several differences. The mutant plant is capable of biting, or in some cases even killing a Sim, including NPC's such as a sims Maid, which many people do to cause her to be able to walk through walls.

How to Get the Mutant Plant
In free-play mode, when your sim has developed enough logic points, have them walk over to one of the incubators, and an option should arise to be able to create a mutant plant. You can choose to sell the plant, or to keep it and have your sim look after it. If your sim does not water it, or care for it sufficiently, it will grow larger and develop an appetite for your sims. If this does occour, the mutant plant will not always be successful in its attempts to eat your sim, and you have about 50% chance of your sim getting a bite from the plant, and still remain livining. If you do take care of the mutant plant properly, you can sell it off for money, and how much you have cared for it can depend on how much money will be added to your families house.

Another way to get the mutant plant is to visit Dudley Landgraab and get your sim to steal one of the ferns located in the back of his house and grow it from that. This can be an easier method if your sim does not have the required logic points or an incubator avalible.