This is the culprit. What kind of plant is it, and what's the best way to care for it?
It's a succulent, similar to Aloe, called Haworthia - this one is most likely Haworthia margaritifera, or possibly H. attenuata. The most common one is Haworthia fasciata, common name Zebra plant, where the white warts are arranged in bands which resemble zebra stripes - the different varieties are often confused, but the care instructions are the same anyway.
Relatively easy to care for, needs a light, free draining soil, will not tolerate sunlight nor deep shade, requires average temperatures, preferably cooler at night and in winter, but not below around 5 degrees C. Watering isn't required very often, they'll survive with some water once a month, but grow better if it's a bit more often. Reduce watering in winter, and don't overwater; in common with other succulents, too much water causes rotting. Further info here http://www.ourhouseplants.com/plants/haworthia
Looking at your photograph, though, I'm not seeing any roots on the bottom of the plant, and I'm not sure what the soggy brown stuff is at the bottom, has it started rotting off already? These plants do produce offsets, but when they're removed from the parent plant, some root needs to be present in order to pot them up separately, so if there's no root material at all on this one, I'm not sure its viable.